In my current games, 8/8 Golemites, this is my research setup:
Mark II Fighters/Frigates/Bombers/Bonus Ship --> Early conquests --> Econ II --> Econ III --> Gravity Turrets --> Fortress Mark I--> 1st Spire City, 3 reactors, 3 habitation centers --> Forcefield II/III, Heavy Beam I/2, Laser Turret II/III, M/C Harvesters II/III, Military Command II/III --> 2nd Spire City, 1 reactor, 1 habitation center, 4 shipyards.
Optionals: Hardened Forcefield I, Engineer II/III, Fortress Mark II/III
Basically, I'm banking on getting enough resources to build a spire fleet as soon as I can, with my main defence as a spire city with a military command station. Oftentimes, I'll put fortresses everywhere on border planets to protect them, as I will have lots and lots of disposable income as a result of my early conquests. I put fortresses down whenever I have excess economy which usually gathers up during the early game when I'm aggressively conquering and don't have the ships to protect everything.