HLMV is what most people use, though mine doesn’t work so I can’t. I just import/hex whatever it is i’m doing into GMod see if it works then come back out (which i’m assuming thats what your doing currently).
You could also, if your just checking the texture, decompile it and open it in a modelling program (i’d suggest Milkshape but then I would :P) and ally the texture(s) onto it to check. I’ve also got another program to do this with but its not something that could be used for GMod skin testing very easily (and requires the model to be decompiled also and converted to a format that is not of Source).
Edit: Damn Ninja’d (but then I did take a while writing this).