Erik, for best possible sound quality, Class AB is the amp to get for subs and highs. Check out Zapco, Orion HCCA, PPI's PCX series, Diamond Audio, Xant, US Amps, JL. For specific models, try PPI PCX2400,PPI pc21400.2, zapco reference 750, Zapco Reference 1100.1, Zapco C2K 6, Orion 2100 HCCA. If you noticed, non of them are class D amps. However, they will sound much better.
Zapco Reference 750 will do just fine. You're not only getting an amp that can power mids and highs but subs too. Class D's are useless except on subs. Reference 750 is 750W bridged at 4ohms. It doesn't say if it supports 2ohms bridged. What you can do is wire the 2 voice coils in series for 8ohms and then use it with the amp bridged. I had the same problem cause I only had 1 18" 4ohms DVC. You'd be surprised how much a clean amp could pound compared to cheap amps with 2x the power. Just so you know, Reference 750 is a fast amp, great for reproduction of mids and highs. There is Orion HCCA 2100 amp. It is a beast, rated 1600W rms. Another amp is Orion HCCA 250G4, rated 800W rms. Since HCCA amp's are very hard to get, I'd go with Reference 750. Great amp.
A fast amp WILL produce better bass also, but you'll notice the biggest change with mids and highs. If SQ is what you're after, then you won't be disappointed at all. This is why it costs more. You'd think it's a simple process, taking the signal from HU and reproducing it as close to the original as possible. Not many amps can do that. The best way I can describe it is, hearing sounds vs being able to pick out every instruement in a song.
Eclipse 33230 sounds like a decent amp but can't tell without specs. If you're going to sell your sub, then get 2 less powerful subs. That way it'll give you more options with an amp. Unless you want to wake up your whole neighbourhood, 300W rms x 2 is good enough for SQ. How much is it going to cost you to the amp repaired? Have you thought of taking that money and investing in a good amp like Zapco/Orion HCCA?