I bought the slightly larger 8.5" x 5.5" 250 set for 80 bucks at overnightprints.com. There's a free option for gloss on both sides that I took. I had some trouble viewing the proofs online with Safari so i just re-uploaded them with Mozilla. The paper is THICK! Colors look great. A few on top had machine marks, but who cares! I will definitely use these guys again.
I tried to write on the gloss with a ball-point pen and it didn't work, but an ultra-fine point sharpie did fine with minimal smearing.