I'd actually make the space gun first (as the first thing you're likely to find that uses mana), skip the meteor armor, the meteor hamaxe, and the lightsaber. If you max out your mana (easy to do) with falling stars, the space gun can be quite useful to start off a boss battle with. It doesn't use any ammo besides your mana, after all, and you can rapid-fire it (It's semi-automatic, so you either octuple-click or use an autoclick script).
Instead of using a lightsaber, I used a war axe of the night (demonite) for my melee combat weapon for quite a long time, and only replaced it once I had enough hellstone to make a molten (hellstone) hamaxe.
I have all the different phaseblades, but only for my collection. They may outclass the war axe of the night, but it has the advantage that it the same amount of damage and has auto-attack (you can hold down the button to keep attacking, instead of having to repeatedly click), and you can make it out of only 10 demonite bars, without needing any meteorite. There's also The Breaker, which does even more damage, but is Very Slow instead of Slow.
Of course, if you can beat Skeletron, you can probably get a Muramasa from the dungeon, which outclasses all of the weapons I just mentioned, and is one of the three best swords in the game (The Fiery Greatsword and the Blade of Grass being the other two; Muramasa is the only sword with auto-attack, and it's incredibly fast).
(Currently I'm using a Sunfury, a grass sword, and muramasa for melee, and various other weapons for ranged combat.)