The Valvetronix amps are incredibly good for highgain, but also cleans and in between tones. DO NOT buy a combo though. Get the AD60 or 120 head and use it on a high quality cab. That's the only way the amp can have the benefit of sounding as good as a tube amp.....since the cabs and speakers from Vox are nowhere near the sound of a high end cab. Another thing you've got to do is use the OD models in conjunction with the gain control.....on all the models, including clean ones.
The Blackface and AC-15 and AC-30 models are best for clean, the Tweed 4-10 and Brit 70's are the best for midgain, and the Recto, Brit 90's, and Boutique highgain are the best for highgain. Always use one of the 3 OD models to add definition and gain to all the models, and you'll be amazed at the tones you can get. Make sure to get the head version.