Do you know much about 3tc engines?...... "But wondering if I can get a reliable built 3TC with the amount I would spend swapping it". 30 years and just now you need an engine rebuild? Do you know what they say about these engines!?

"I'm sure all this sounds pretty generic but I'm aiming for more power than the stock 3TC can do but also being street legal"..... You do know you can get 1000 HP+ with the engine you are trying to swap out right?
I guess there is no way to help you my friend because you have too many problems!

You are looking for the cheapest engine until you can go efi and turbo but cant go megasquirt. You want to swap just to get more HP when you can get whatever power you want with the stock engine. The icing on the cake is that you also live in California.
3tc engines do not break, people break them. If you find an engine more reliable than a 3tc or Toyota engine, please let us all know.
Closing tip points for you. 1. If you are set to go with efi then get a 4ag, you will get the ecu and everything with it. Negatives? You want cheap and you have to fabricate to make it fit. 2. Get some head work, cam, clutch, carb upgrade, ignition upgrade, headers and tubing. Then let us know if its a reliable, fun car to drive and a street legal car.
But wait, you live in California...

Looks like 4ag or make it a racing car and be done with it.
Have you thought about selling the car or trading it for a gts?