sendoh, Ah, the GP01, what a classic. I really like it's big, pointy horns, and those thrusters (I think that's what they're called, geez my memory fails me). As for my favorite, that's hard to say... in terms of the Gundam universe in general, that's Dynames. In terms of SD Gundams, that has to be the 00 7 Swords (but I have yet to get one, I don't want to get it off eBay because I know I can get it for so much cheaper at my local import shop, who doesn't have it yet D: ).
I must admit that my experience with models in general is somewhat limited. I guess that's why I've never used a pen scriber, but thanks for the tip, I'll definitely check into it. Any specific brand you recommend? Or will just any brand do?