I have an Alpine 3527v 4 Channel Amplifier. Here are a few stats on it:
40x4 RMS at 4 ohms.
50x4 at 2 ohms.
Bridgeable to 2 channels.
Built in adjustable crossover for all channels

It's kinda beat up but works fine, i just tested it out like 20 minutes ago.

Here is a pic of it:


I'm asking about 50 for it. The price can be adjusted.

I am currently in Gwinnett County right now(Lawrenceville). but mon-thurs i will be in marietta. PM or call me about the amp: 770 337 0414