I'd personally go for a modelling amp. You don't really know exactly what you're looking for in an amplifier yet, and I personally find modelling amps to have a higher quality at low pricings. Both the Peavey Vypyr and the Fender Mustang get pretty good reactions on the web. The Vypyr would probably be better for the high gain stuff while the Fender offers better clean sounds. If going for for a tube amp, I would probably recommend the Blackstar HT-1/5 amplifiers, but I believe those are above budget (A good might be had though, you never know!).
- Peavey Vypyr: Intended for metal/high gain, but still able to play other music of course.
- Fender Mustang II: Great cleans, the gain stuff will be less good though.
- Blackstar HT: More expensive, tube amp. A personal favorite for the price.
When on a budget, it's important to know what you want. You can't have everything, so your choices are important! Try them out ideally, because it might theoretically be perfect but lacking once you play it, or you might even be pleasantly surprised. Most amps have their merits if you check them out (but the Line 6 Spider series or Marshall MG are the work of the devil