Any guitar players here?

Hi, I'm looking to upgrade to a more powerful amp for my electric guitar. Right now I have a fender 90 watt amp with a 12in speaker, but it seems to be lacking in power a bit.

Having only one speaker make me have to really play it loud which then creates a lot of feedback.

To make a long story short, I'm looking for a kick ass amp, hopefully with 2 speakers, for around 400 bucks. Anyone have any suggestions for one?

And/or is there something I'm doing wrong with my fender amp that makes it such a pos?

(BTW I play mostly punk guitar. Loud, distorted, fast power cord type stuff)