Out of that list, I only have the Mustang (just got the Maverick as well but haven't gotten the chance to use it yet). Anyway, the Mustang is AWESOME! It's got a nice curve and isn't too large or too small. It's pretty close to an average size penis, and did I mention yet that it's awesome?
Buck and Lonestar are larger, Mustang is an average size and Spur is quite small (a great anal dildo). It really depends on what size you're looking for. They're all great options though. Vixskin is a wonderful material!
The mustang is AMAZING for all your mouth related sexy time activities! I use mine to practice on and it turns me on just giving a BJ to it because it feels so real and with some imagination, it is the closest to life like as you can get.