Our Guitarist Wants a New Head Help?!

[jufros]

So the rhythm guitarist in our band plays a dual-humbucker guitar through a Peavey Windsor. He liked the Windsor for the money but is looking for something more reliable and with more character. I'm a bassist, and while my knowledge of bass gear is definitely extensive, I don't know much about guitar amps and cabs. He's looking for tubes, punchy mids, lots of clarity and presence, and an excellent clean sound on the clean channel. Any recommendations? He's looking to spend about 700-1000.