I have sold plenty of things on this forum and it's pretty rare that I hear a horror story. Most ppl on this forum are good guys/gals.
No, buy from www.getbmwparts.com
You can get the standard or GTS (satin black finish) at a great price. I got mine for ~$2250 shipped. Came in exactly 1 week.
You can use the same TPMS from your old wheels. That's what I did, but you will hafta swap them if you want to throw the old wheels on for track or winter unless you can deal with errors.
ESS VT2-625 w/ DCT Software | Stack Gauges | 19" BBS FI | Dinan Stg 2 Suspension, CF Strut Braces, & Pedals | Fire Orange Brembo GT 380 F&R | Akrapovic Evolution | Vorsteiner GTS-V Lip, CF Type II Diffuser, & White Piped Floormats | Platte Forme CF Side Skirt Extensions | BMW Performance Seats, CF Spoiler, CF Mirror Covers w/ M5 Paint Scheme, & Performance Steering Wheel w/ Custom White Stripe