Just read your other thread, if you can't solve a fuel delivery problem, a major fuel injection swap is out of the question. I don't mean to be insulting but it's a lot of technical work, and cost prohibitive to pay someone else to do.
Sounds like you're at the mercy of mechanics to a certain degree. If your car runs fine temporarily then it is something that can be easily fixed. Don't give up on it!
Rather than drop a different engine into it, you could also just update the EFI system. This would certainly be less expensive than a new drive train and require much less fabrication work. Mechanically, the B30 is fine and you can still get any/all parts you may need for it. You could even save all the Djet bits in case you wanted to go back to stock, or sell the Djet bits and finance your EFI upgrade. Selling a Map sensor and a set of trigger contacts will get you most of the way there!
Either option will require patience and time. Lastly, neither of these will likely fix your fuel pump issue. Keep at it!