Car is running 210Kw at the wheels. Current exhaust is 3" upto the muffler with twin 2.5" exits.
Option 1 - Rebuild)
Can mufflers be cut open and rebuilt ? ie repacked, baffles, pipes etc replaced.
Option 2 - Re-make)
Can a fabricator make my muffler based on the dimensions and internals of my current one ?

Option 3 - Replace with bolt on cat back)
Based on the Pheonix power design this is about the only one I can afford ($590NZD delivered) and I can fit myself. Although some say its loud, but the Youtube sound clips sound great.

Option 4 - Custom)
If option 3 is to loud id like to have something custom built out of 2 larger cannon style mufflers like this (TKO system with 7" Magnaflows). Will be louder than my Fujitsubo with baffle design but quieter than XS-power system with its smaller mufflers.
I have no idea what sort of mufflers to go for (Magnaflow, Flowmaster, M&H, Flowsound, Adrenaline-R (NZ made), Dytech)
Do all barrel style mufflers sound loud ? even if im running 2 ?
HELP !! this rattle is driving me nuts and after spending 8K on the car last year fixing it up I want to enjoy it this summer.
My budget is $500 - $650max and car will be capped at 300 RWHP when it gets its tune so must be able to flow well.