kenwood is pretty good, mainly their excelron series that i've heard good things about. look at us acoustics amps too though. their USB-4065 does 65x4 @ 4 ohms for about $130 shipped. if that's too much power you could just turn the gains down a little and you should be ok. another good amp would be from soundstream at millionbuy.com ( http://www.millionbuy.com/souega4120.html ). if you want something that doens't put out that much then look at profile amps that say they do about 60 or so watts. realisticly they would do about 40 in general. for about $100 shipped you can get what you'd need. (http://thezeb.com/caraudio/profile.html ) you can probably find even better prices than that though.
must be a rare case, i wouldn't give up on them with just one expeirence, i've only heard good things about them, never one bad thing. especialy since they rate their amps at 12.9V. pretty generous and underrated. I don't think you'll have a problem with soundstream though, i just put one of the 4 channel 85 watts x 4 amps in my brothers car running 2 coax speakers and a sub and it seems to do what it's rated at. it's really good for the money.
I can personally vouch for US Acoustics. I had the USB-4050 in my Mercury a few years back, and I never had one single problem out of that thing. It performed like a champ, never overheated, and sounded great. If I ever decide to buy another amp, I will definately go with US Acoustics. You can't beat the quality for the price.