No just use republic the whole time, it's better than Demo for this (cash bonus, explore bonus, demo has 0% market commissions but you're hardly selling anything)
Step 1) Build about 200-250 industries and get bpt to 45-50. 100% turret production, sell all the turrets over and over. You don't actually need more than 5k, so sell the rest on the public (and private for your first 70 turns).
Step 2) 1900 land, 45 or 50 bpt, the rest all labs (you can knock down the industries).
Step 3) Tech the 50k bus/res
Step 4) Tear down the labs and replace with enterprise zones and residences. You're a casher with good tech now