My 1st non stock build, how would you rate my box (0-100), any suggestions for more efficient hardware choices are appreciated

im on my 1st non stock build which i plan on turning into nearly the best possible gaming box that the mobo can handle while trying my best to be as cost efficient as possible (needs to be profitable to resell)...it is a dell precision workstation t7400 ($75) it had a bad psu which ive replaced with another 1000w from i believe a dell precision 690 ($30), it came with a wd caviar blue 500gb hdd, dual intel xeon e5450 2.66ghz quad core processors...im keeping the processors and ive already upgraded the ram with memory riser cards and 16 dual channel samsung 4gb ddr2 667mhz ecc fbdimm ram sticks (ram=$25,mem risers=$19), 2 pci e 2.0 x16 XFX One 1GB DDR3 HDMI DVI VGA video cards ($33), a Creative Labs SB0460 Sound Blaster X-Fi PCI Sound Card ($14), im looking at getting 8 600gb wd velociraptor hdds (estimate $180-240) to run in a raid 0 with a samsung evo 850 500gb or 1tb ssd as a main storage...my goal is to spend as little as i can but to have just about the best performance possible and seeing as its an older mobo i dont want to waste resources on hardware that'll be bottle necked by the available bandwidth of the pci slots, mobo, or cpu's... the mobo has 2 pcie 2.0 x16 slots wired @ 16 each, a pcie x8 slot thats wired as 4, 1 pci2.0 slot, and 3 pcix 2.0a slots...the sound card is for the pci2.0, the 2 video cards are for the pcie2.0x16 slots (im open to suggestions to upgrade these), i want to run sataIII hdds on a hardware raid either from a pcix or the pcie x8 (wired as 4 tho)slot (i'm worried that these slots will bottleneck the sataIII if so can i run the 2 video cards off 1 pcie2.0 x16 slot and run the raid off of the other, or should i just run with sataII)? then i want to add a pcix to usb 3.0 card (if theres 1 made), the fastest possible wlan card, and an ethernet card...sorry for the long post, Ive read a ton of these threads and im just trying to be as descriptive as possible on the 1st try for anyone that actually reads all of this and gives me their input or advice i greatly appreciate it....
box summary:

Hardware on hand:
Dell workstation T7400 mobo
2 Intel Xeon E5450 quad core 2.66ghz
Samsung 64gb 667mhz ddr2 ecc fbdimm ram
PCI- Creative Labs SB0460 Sound Blaster X-Fi PCI Sound Card
(2) PCIE 2.0 x16- XFX One 1GB DDR3 HDMI DVI VGA video cards

Intended hardware:
PCIE x8 (wired as x4)- 8 port sataIII raid card (or sataII)(need suggestions)
8 sataIII wd 600gb velociraptor hdd's (or should i go with a sas storage system)
500gb or 1tb samsung evo ssd (will this make an impact on the system that would be worth the additional investment)
PCIX wlan card (need suggestions)
PCIX ethernet card (need suggestions)
PCIX card of some sort (need suggestions)

i havent had the chance to look into sas yet but will i get more bang for my buck running a sas storage system instead of the wd velociraptor hdd setup and lastly am i making the most efficient use of the pci slots and intended cards (i really dont want to waste $ trying to run hardware that'll just end up being bottlenecked by bandwidth limitations)
.......hope i didnt miss anything, typing this on my phone was a mission