I would suggest either a Antec 300 (these were going for around $30 a couple of months ago), like you originally had, or a HAF 912 for a case.
If you are going to be doing music production, I would suggest you go with a i5 2500k, as that gives you the ability to overclock and also is future resistant (who invented the word future-proof anyways? People always say "future-proof for another 3 years" or something, and it makes no sense).
Also, I suggest a GTX560 Ti or a GTS450.
In terms of HDDs, if you definitely want a SSD, go for it, but I would buy 2x500GB F3s and put them in RAID0. I know people always say that RAID0 is unsafe and all, but my main rig (which is on about 14 hours/day) has been using those 2 maxtors in RAID0 for the past year, and I got them from dumpster diving. No issues yet, although I do have a backup just in case.
I also suggest a DX or something similar for a sound card.