Currently DSN is the go to guy for some 127 PAMs and most Titanium PAMs (because only he carries them). If you want something besides those models, and care about the small details, then the "Ultimate" series will probably suffice.
However, if you want the most accurate rep, without getting immersed in modding, then go with Vac. Buying from Vac will basically save you from buying a base rep, then sourcing more accurate parts, sending those parts and your base to a mod or two, then finally sending it to Vac /Ziggy/Goin/Francisco/etc for reluming. This means that your rep will spend less time as a parcel, and more time on your wrist