SSD, Raptor, Cheetah, or RAID

First off, I've been getting help from TH users for years and I love this forum. But I finally have a question. I've found several threads here regarding different storage solutions, but my situation is slightly different and I can't make up my mind. This was the closest I found:
http://www.tomshardware.com/forum/248547-32-raid-sata

I'm looking for a boot/OS disk and here are the options I'm considering:

SSD - $110 minus $30 MIR for 32GB. http://www.newegg.com/Product/Prod [...] 6820227393
Raptor - $140 for 150GB. Self explanatory.
SAS - I have a 146GB Cheetah (ST3146755SS), but I need a controller. $120 seems steep for an entry-level card.
RAID - $70 for 640GB. 0, 0+1, 1+0, 5, 6, or 10 - I'll cross that bridge if I go this route. I have a WD 640GB Blue that has been in use for about a year, another one still in its static bag, and I would need one more (maybe 2). The data currently on there can be migrated.

I have a WD 250GB for my OS/programs that is about to fail (click, click). My first priority is speed, second is storage space, last is redundancy. Heat, power consumption, and noise are not factors to me. The drive will be used for OS/programs and whatever games I can squeeze in. Usage - 50% internet/Word, 30% games, 15% video watching, 5% video/photo editing. As it sits, I've got 1.2TB and I'm hurting for space. Dropping down to 32GB by way of SSD would suck, but it's not the end of the world. $150 is my ceiling if anyone thinks of another option. $100 is my target. Thanks in advance.