4670 is going to be faster, its been commented on many times on the web as being closer to a 9600GT in performance than the 9500GT. the 4670 is also targeted at the 9600GT's range as well. but for a little more, a 4830 (which is just a de-tuned slightly lesser spec'd 4850) can be had for close to same price range ($100 to sub $100 range)...
$5 more gets you this:
Newegg.com - ZOTAC ZT-96TES4P-FDR GeForce 9600 GT 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Desktop Graphics / Video Cards
more than double the 9500GT's performance, can't see paying $80 for a 9500 card that isn't nearly as powerful as one of the 9600's... hell even the newer revised "neutered" 9600GSO's at that price would be a better performance deal, at roughly 50% more stream processors (48 vs 32 on the 9500, 9600GT has 64, the old 9600GSO had 96, but reduced memory bandwidth so came out similar performance as the GT models) & memory bandwidth (192-bit vs 128 on the 9500... Hmmm, seems with the revised models the boosted the memory bus to the GT's 256, so yeah, its still going to be more powerful than a 9500GT anyday).
Newegg.com - EVGA 512-P3-N963-TR GeForce 9600 GSO 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Desktop Graphics / Video Cards
as to the RAM,
cheapest lowest CAS 4GB kit of 1066:
Newegg.com - OCZ 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory - Desktop Memory
cheapest Lowest CAS 4GB kit of 800:
Newegg.com - G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Desktop Memory
its actually cheaper by a couple bucks to go with the faster clocked RAM. which should make up for the higher CAS 5 rating over the CAS 4. Even if the Memory is only run at 800MHz, it should be guaranteed to run at 1066 vs the 800 stuff if you should want to do some mild overclocking down the road with the Black Edition AMD.
that's 2 bucks more towards the video card or shipping for items.
agreed on the hard drive though.
$100 is a waste on a 74GB drive, even if its a Raptor, granted its at almost half of what it cost a couple years ago for those things. its actually cheaper or same price range to buy 2x 250GB drives & run them in RAID 0 for similar performance results... its a two fold deal too, you have 500GB of drive space, at performance levels of the Raptor for same price, yeah RAID 0 has its downsides, if one of the drives gets corrupted you lose the whole array & all data on it... but the same can be said of using a single Raptor, though some data may be recoverable on it, but most people will just concede & wipe it clean & learn from their mistakes & make periodic backups of important data.
even cheaper yet grabbing one of those 32MB cache drives like the one JLK linked to above, with that you still have cash to spare on a 2nd smaller drive to use for back up purposes if you want.
I can't say anything for the Western Digital 32MB cache drives, but I know the Seagate ES.2 32MB cache drives are pretty fast as well, though my 250GB model cost about $75-80 last spring when I bought it, it was still worth it IMO, performing almost as good as my old 74GB Raptor I had a couple years ago (Only reason I had one of those was because I won it in a contest on another forum).
I'm running 2x Western Digital 250GB 16MB cache drives in RAID 0 and their even faster yet than the Seagate & Raptor drives. and then I have a single 500GB Western Digital 16MB Cache for backing up stuff off the other 2 drives (well 1 drive & 1 drive array)