Because of the amount being spent:
Either amp that can push more than 50 - 80 RMS watts (this is something like the average sounding level) can help you a lot for live, studio, practicing, ettc...plus, it will rock and beat even the bass player.
Here are some you could see in
www.musiciansfriend.com for the range 250 - 300 $.
Amp Output Cab. Price
Behringer Ultratwin
GX212 2x60 2x12 299 $
Behringer V-Ampire LX1-112 2x50 1x12 299 $
Line 6 Spider 112 1x50 1x12 299 $
Line 6 Spider II 112 1x75 1x12 299$
There are several amps out there that will vary from 400 to 500 $ that may help you a lot, like Fender ( I would go for
the Hot Rod Deluxe, or
the Cyber Deluxe), Marshall (there are so many, and I'm not a fan of Marshall). Also the Line 6 - Duoverb (which is two amps in one...you can use two different amps at a time in different speakers) would be a great choice.
From those above, I would personally go for the
Behringer V-Ampire or
the Line 6 Spider II. They both deliver a nice amount of sound, the've got effects included (the behringer can be upgraded via internet) and because of the fact that the guy that plays with me has
a Line6 Spider I recomend you highly this choice (it has a collection of the best ams, like marshall, fender, mesa. Though it does not sound exactly like them , but they have a close range.) I have tried it and you can use it for either style you will without having to change to another amplifier...plus, you've got effects...good effects.
Well, if you want, take a look to Harmony-central.com and go to reviews. Then, Guitar Amps by manufacturer and clik on Line 6. find the Spider 112 or the Spider II 112 and read the reviews...
Hope I helped.
HEY THIS GUY IS NOT GOING TO BUY A MARSHALL HEAD OR
A VETTA OR SOME SORT OF EXPENSIVE AMPLIFIER. THOSE I MENTIONED ARE GREAT CHOICES AND GOOD SOUNDING AMPS. IF HE WANTS HE CAN UPGRADE WHEN HE HAS A COUPLE OF THOUSANDS OF DOLLARS AND BUY HIMSELF A MESA HEAD WITH A 4x12 CAB...