pretty all the Bose systems are fully amp'd, aren't they?
As per Mart's offer: if you get the correct wiring loom and a decent headunit and sound quality should stay the same/better: the "BOSE" part of your kit is all AFTER the headunit... the only thing different to your headunit from a base spec one is that it's been coded to show "BOSE" on startup: I've seen at least one car that had been coded with the "BOSE" startup and had BOSE badges on the grills, but had no amp / sub (so not BOSE)!