Remapping the GT4: Worth Using 95RON?

[Hate]

When it comes to remapping my JDM celica GT4, I was thinking the other day if it was worth having it mapped using 95RON as a base fuel...

I'm not going for massive power with this car anyway, I'm thinking 300BHP is prob my cieling (cause you have to start spending silly money after then, 300BHP is an exhaust, intake and boost controller). and a 95RON map would be useful as currently the JDM ST205 has no map below 98RON.

I currently use optimax.

Thoughts?

 

[Hate]

Im also a little confused, the celica club recommend staying away from a unichip and getting a boost controller and getting that sorted.

I guess this would have the same effect?

 

[Hate]

well, I can get a relief valve for the ST205 for 25 quid that bumps the boost from 0.9 bar and up it to 1.0 or 1.1 bar.

I don't want a loud exhaust, but apparently if i keep the rest of the exhaust system but replace the cat with a downpipe and sort the intake I could comfortably get 280BHP with the downpipe / intake / relief valve.