Hi Fuze,
I also download only 320kbps. With the payment problems on MM/Sparks I've been using Millisong.com . I find their prices are cheaper than MM but they have a smaller catalouge. They add albums regularly but are pretty slow and sparse with new releases, seem to add lots of older albums and jazz though. The downloads are pretty fast and come as a zip file that includes a jpeg of the cover, but I have to edit the name of every track to match my naming convention (artist - track number - name), whereas you can set this to be automatic in MM.
Another site I've been using is
mp3fiesta.com . The problem with this site is that the bitrates are all over the shop, probably only 10% or so are in 320kbps. So you have to hunt around quite a bit. It's also hard to know when they add albums. The benefit is that it's quite cheap - around $1 an album. As an example I downloaded a 36 track double album (at 320) about 2 weeks ago for $1.80 that was $7.50 on MM/Sparks. The catalogue is quite large (but of varying quality). Downloads are quite fast but you have to download tracks individually using Flashgot or similar. Some editing of track names required, but a little less than millisong.
Another site that is trying to regenerate at the moment, but isn't operational yet is
iomoio.com . This one looks promising. Most music should be at 320kbps, the catalogue looks to be a decent size, prices are a flat 10c a track and there will be a very good bonus plan (effectively halving the cost for larger payments). They will add albums weekly and will take requests for additions. Obviously as it's not yet operational I have no experiences to share, but I'm looking forward to it's commencement.
Hope this helps,
Cheers,