Finally I have managed to find out that the RB20 swap is possible to do! Now I just need to sell all my CA18 parts and try to work much as possible to get the money I need for it. Also I bought this harness bar from a good friend of mine and installed it with my girlfriend. Next thing to do is to measure and calculate that the angle of the harness is correct.
Next weekend there is an outdoor car show where my car will be, hopefully the last one without an engine.