Hi!
With Super Breeder you should have minimal money problem, because they breed so fast. There's just one thing you must pay attention to: morale at a planet must be at 100% for them to breed with 800% bonus. When planet gets to ~3B pop it usually pays for itself, and that's the treshold when you can start building/buying buildings on that planet.
like start off with a heavy colony rush. I start off first couple turns purchasing a research lab and factory and an econ building soon as I can
I'm sorry, but that build order is not a good base for "heavy colony rush". For Super Breeder you need a significantly faster start. I'd suggest you to build ONLY fastories on your HW. The goal for Super Breeder is to BUILD each turn a colony ship, fill it with max pop and send it (mostly) blindly to distant stars. You colonize planets at their max range, the only exception being class 10+ planets. Those you better take ASAP.
If you're interested, long ago I started a topic regarding exactly the same theme: Playing with lots of planets - how to financially survive first year?. It's for DA, but you can find something usefull there.
BR, Iztok