I was actually going to buy a Vyper before I settled on a Valveking. It's a cool modeling amp and you have a lot of customization. You should be able to get a sound that you like out of it.

Did you get the one of the Sanpera foot pedals?

EDIT: OH! And don't forget to try the guitars ON a Vyper if you can. Preferably the same kind you own. That way you know exactly what you can do with it and what it will be like if you bought it. If they don't have a Vyper, try something similar to the sound of a Vyper. Just don't test on some cheap because obviously it won't sound too good. And just because I didn't talk about Schecter as much, doesn't mean it isn't good. You may try one and like it a lot so consider it too.