They're military battalions. It's safe to assume they've got all they need with them.
I'd sugest bringing down the cost of the heavy transport to 2200$. A chinook isn't much more expensive then a destroyer. Though that'd mean the amphibious transport could cost 1900$ as well, since it's pretty much double a freighter with some extra armour.
Also, here are some references for aircraft wings:
Fixed-wing aircraft need a landing strip to refuell and resuply once they run out of either. VTOL aircraft can land on carriers. Stealth aircrafts are very hard to detect without specific instalations and even then they have a decent chance of slipping trough. Sub-orbital aircraft can only be attacked by interceptors and air superiority fighters, though the last have only a 50% chance of succeeding. Most aircraft need a runway to launch and land and thus can not opperate from countries where this infrastructure has been destroyed. Land-based forces will automaticly make makeshift runways for aircraft that can use these (Interceptors, Spy Planes, Transport Planes and all Helicopters)
Fighter, 1700$: Standard issue fighter to keep the airspace clean. Medium range. Can take down a Fighter/Interceptor or a Bomber on it's own. Comes in a VTOL version for 2200$, a stealth version for 5500$ and a stealth VTOL version for 7000$
Fighter/Interceptor, 1900$: Fast aircraft with poor manouvrability desinged to intercept and destroy enemy bombers. Has a short range and is capable of taking down 4 bombers, but gets taken down by normal fighters. Due to it's small posture, it's always deployable from carriers and can be deployed from makeshift runways made by a land-based squadron. Comes in a stealth version for 5900$
Air Superiority Fighter, 3000$: Heavy anti-air fighter. Long range, but incapable of attacking ground targets. Can take down 2 fighters, 3 F/I's or 2 bombers. Comes in a VTOL version for 4200$, a stealth version for 8000$ and a stealth VTOL version for 12000$
Bomber, 1800$: Standard issue bomber. Long range. Has a minor chance of taking down a fighter, but stands little chance against interceptors or air superiority fighters on it's own. Can do modest damage bombarding. Comes in a stealth version for 6800$
Strategic bomber, 2200$: Fast bomber carrying light anti-tank payloads. Short range. Can usualy outmanouver normal fighters long enough to drop it's payload. Used to take down panzer batalions or medium-sized ships. Roughly as powerfull as a medium tank but stands little chance against interceptors and air superiority fighters. Comes in a VTOL version for 3000$, a stealth version for 7000 and a stealth VTOL verion for 10000$
Fighter/Bomber, 2700$: A more manouvrable version of the Strategic bomber, but it sacrifices on payload. Short range. Counts as a fighter for air combat roles, and as a medium tank for ground combat. Comes in a VTOL version for 3700$, a stealth version for 9000$ and a stealth VTOL version for 130000$
Tactical Bomber, 3500$: Carries a very heavy payload or a nuclear warhead. The weapon of choice for taking down large industrial complexes or enemy fleets. Has a tail gun capable of taking down single fighters with relative ease. Comes in a stealth version for 11000$
Spy Plane, 1700$: Standard issue plane for spying upon your enemies and your allies alike. Long range. Is always deployable from a carrier and from make-shift runways made by land-based forces. Comes in a stealth version for 3500$, a sub-orbital version for 5500$ and a sub-orbital stealth version for 7000$.
Radar Plane, 3500$: Extremely long range. Keeps an eye on all aircraft in the surrounding area, making intercepting them much easier. Has little defense itself but can scramble the opponents radar to buy time. Doesn't come in stealth version due to it's active radar. Comes in a sub-orbital version for 7000$
Refuel plane, 1500$: Cheap way to upgrade the range of all aircraft except interceptors. Has a high range. Utterly defenseless, they are best deployed far away from enemy fire. Can refuel several aircraft before having to land.
Transport Plane, 2200$: Medium-sized aircraft with a long range but relatively slow. Can land on makeshift runways but not on carriers. Can carry 3 infantry squadrons or 1 armored group.
Heavy Transport Plane, 3000$: Large aircraft with a huge range used to haul big pieces of equipment around. Unlike it's smaller brother, these need a runway to land. Can carry 4 infantry squadrons or 2 armoured groups.
Helicopters are short-rangesd and can be attacked by all ground forces except of artillery, though with varying succes. They come in stealth versions but have no sub-orbital capacities. Most can be deployed from cruisers and larger ships. They can refuell and resuply from any location containing a land-based squadron.
Helicopter Gunship, 2200$: Short-ranged, slow aircraft capable of dealing surprising amounts of damage to infantry batalions but is less efective at taking out tanks. Is vundrable to direct fire from non AA ground forces. Is deployable from any ship larger then a Destroyer. Comes in a stealth version for 6800$
Tankbuster Hellicopter, 2500$: Short-ranged, slow aircraft capable of tearing a tank squadron apart. Is reasonably effective against infantry but can't lay down enough fire to realty punish them. Is deployable from any ship larger then a Destroyer. Comes in a stealth version for 7600$
Sub-Hunter Heli, 2500: Helicopter equipe with sonar buoys and depth charges. Is useless against land forces, but it deals damage to surface ships equall to a corvette. Has double chance of detecting submarines. Is deployable from anything larger then a Corvette. Comes in a stealth version for 7600$