Get a Sherbourn 5/1500A. It works great with low-impedance speakers and you'll have enough money left over for a really nice DVD player.
Most if not all of 5ch amps are solid-state devices and as such will drive 4 ohm loads without problems. The quality is another issue... on your budget you should find very good 5.1 components especially if you are willing to buy used/demo gear.
I like EAD and B&K stuff. EAD Ovation + B&K 5ch. will work great with your speakers.
If buying new maybe one of latest Pioneer Elite or Denon receivers may be an answer.
I like EAD powermaster amps.Tried other amps and these seem to be exceptional value all things concidered.I know that there are many amps to choose from some better and MOST are worse.I drive maggies with a PM 1000 and this is the first amp that can deliver the bass that many people say maggies lack.Maggies that lack bass lack a good amp with control and authority. The other 5 channel amps I've bought and tried Golden Theater GTA-1 200x5 ,Earthquake Cininova Granda' 400x5 , Acurus 200x3 , Sunfire signature 600x2 ,NAD 2200 100x2 , Sansui BA-3000 170x2 and countless other Japanese models. Good luck on your choice as this forum will led you in the correct direction saving you money and time. Most everyones suggestions have come from first hand experiences.