RB24 is a waste of time.
Plenty can be done with the RB20. Need to spend a bit on cylinder head work though if you want the numbers and torque.
Leave the bottom end for now, take off the head and put on a pre-ported one with bigger valves etc. Go Pon cams, Angry German with surge tank injectors and a NISTUNE or I have an ECU in my 20 which has already been chipped and I won't be needing it. Already set up for 550's and a Z32AFM
I can't use AFM with the new setup as there is nothing big enough for 1rwkhp
So all you'd need would be injectors, fuel system, JJ intercooler and a couple of other bits and pieces. Could easily get 220rwkw on that turbo.
Then when you can afford more of an upgrade (or even want one) do the cylinder head and go bigger turbo/cams. You can make 235rwkw on the stock cams with stock/untouched head.
You can also do 205-210 rwkw on stock injectors and AFM too but I would be careful running them at those levels.