with that kind of money i would just splurge on a 1980's Yamaha MX-1000 power amp and be end-game since that amp can push 1000w into a 1ohm load. it would even make short work with pair of Apogee Scintilla speakers known to be amp killers due to their impedance of 1ohm nominal. you can easily score a MX-1000 under thousand bucks. hell might even get lucky and can get them under 600 on the used market depending on condition.
4ohms is not really a difficult load to be honest. you can look at some vintage amps too(sansui,kenwood,scott,H/K,pioneer,marantz,sherwood,sony,ect.) and save yourself some money. most of them will have zero issues with 4ohm speakers only brand i know that can drive very low impedances under 4ohms with no sweat from their BOTL to TOTL list is the 1980's yamaha power amps. even the M-40/45 can push up to around 390w into a 2ohm load and are all switchable class A with insanely good cooling. they barely even run luke warm in class A operation and built insanely well with heavy metal cases and cool looking red power meters. yamaha made good receivers as well. to save money i would just go with something like a M-65 and C-65 combo. for brand new and current model amps Krell makes some killer amps still and known for their high quality components and big toroidal power transformers.
also don't worry too much on the amps power rating(wattage) since speakers are always measured at 1w@1m@8ohms. Maggies are pretty sensitive speakers and have good sensitivity so loudness wise you'll probably won't be pushing more then a few watts into them. it's the dynamics and impedance dips and spikes(planers are very flat across the frequency spectrum in their impedance so don't have to worry bout this part) that use up the extra power and rest of the power is dissipated as heat in the voice coil of the speaker and the heatsink of the amp but it doesn't mean of course you can't use the extra headroom especially if you have the money for it. you get the best you can for your money as always.
