ITR reflash vs ITR ECU

[wolf74]

I have a 2004 RSX with ITR cams,PRC manifold and ITR Exhaust
I was told that I should get a K-pro, I am currently running a ITR PRC ECU and would like to replace it with my PRB ECU reflashed to the K20A type R spec.

The ITR ECU is tuned to run 100 Octane I assume and the Reflash 91 Octane.
The Octane rating in Jamaica is 90 and as such I'm looking that the reflash is a better bet than the PRC type R ECU I'm currently running.

I know K-pro is best but I can not afford that now
Please Advice