No problem! The jackhammer can fit on just about anything we'd want a lightweight, rapid-fire autocannon, be it an IFV, a helicopter, a plane, or even a transport. Of course, if we do design is separately, that's cool too.
In fact, here's an idea for a transport while I'm at it:
ATH-53 "Bottlenose" Hovercraft Transport. This amphibious troop transport uses the principles of differential air pressure(achieved using large blowers) and an enclosing rubber skirting to "hover a few feet above the surface, allowing it to traverse water as well as land with equal ease. This allows it to access many more beaches than a traditional transport can, as well as ensure that it's cargo is deposited directly onto land.
The Bottlenose is large enough to carry a single T2 Breaker tank, as well as a dozen or so troops and a week or two of supplies and ammunition. it also has twin Jackhammer autocannon positions on side blisters, mounted in such a way to provide near 360 degree coverage between them(including the ability to fire at most close air targets), as well as positions to mount Sorraias as needed. Finally, the blowers and propulsion fans are powered by a turbo-charged marine diesel engine for maximum efficiency.
[Ship, very small, specialized][target cost:2 ore 1 oil][New Techs:25mm Autocannons, Hovercraft]
Yeah, I know makin gthis a hovercraft combined with the autocannon would mean we'd field a lot less transports than New Guinea, but ours would be a lot more capable so the tradeoff is worth it.