Yeah, I've played that thing before, and I play the same style as you do. You won't get quite the "Marshall tone" that folks tend to go for, but the amp is really really versatile. Definitely high quality. I wouldn't say you're making a mistake at all.

But of course, the question is really up to you! Have you played it before, and do you think that it gets the tone you're looking for? If you haven't played them, I know Guitar Center is carrying them now (they didn't used to, but they do now), so I'd go and try one out.

Hope it helps
For rock and blues I recomend the Peavey Classic 30, its cost a bit more but they can be found used around the price of the VK. The VK is a good for what it is, a 400 dollar tube amp that can do higher gain stuff, but it is way more modern vocied. Don't get me wrong for 400 dollars it is its awesome, but if your looking more of a bluey and or more rocker marshall type sound look into a C30.