Yeah, eco II tech is pretty much a must, as the economic boost it provides is incredible. I usually prefer to wait with upgrding to level 3 until i hit the cap for mark II stations, as it feels like a waste to have so many unused stations early on, when you dont have enough systems.
Fighter/Bomber II are also always my first pick. Bombers are extremely useful in combat, hard countering quite a few objects, and fighters are so cheap its always nice to have more of them.
Tachyon tower if the AI has cloakers, warp sensor because its cheap, flagship, basic turrets mk-II, hardened and regular forcefields, engineers mk-2 and scouts mk-2, bombers mk-3.
I grab all these as soon as possible, then proceed to balance between getting better turrets and mark-III fleet ships. Also, raid starships get researched along the way.