For a first vibrator I think it's best to go with something fairly innocuous-- the fukokou is probably a good choice -- though i've heard that it's pretty tame vibration wise.. and obviously there is no possibility for penetration. Why not try something like this:
<url>
http://www.goodvibes.com/cgi-bin/sgi...EQC=3&TRAN85=N</url>
I think it's a good idea to avoid anything too penis-like (might be a bit scary for a first timer) or overly large.