Replacing 987 stereo

[PartialFish]

Even in an open car, I prefer the best stereo I can install. Already in possession of an Alpine 9887 head unit, accompanying amp, & front & back speakers I'd bought to install in my old vehicle, I went ahead & bought a 2005 Boxster already knowing the center console problem,et al. Question is, what has to be done to replace all that mess? My car has the standard stereo "upgraded" with a subwoofer, mainly. I'd appreciate help on this, and am frustrated with this el-cheapo approach similar to that on a GM or old Japanese car, with custom center consoles. Is there a console face replacement that'll accomodate a single-DIN head unit? How hard is it to replace the speakers (I have front Polk components ready to go) & do they have to be rewired (I don't have Bose). I'd sure appreciate hearing from someone on this!