Yeah it looks like I was worried over nothing... I went over to Subsim.com forums and Win 7 is ok for SH3 and SH4.  

I think I put together a comparable RIG at magicmicro... I used the ATI 5770 as recommended by Spikes. Everything look ok? I just can't see myself putting one together right now.
$1,121
CURRENT CONFIGURATION
   PARTS : CPU : Intel i7 CPU
   Intel Core i7 920 2.66GHz (Quad Core) 8000K
   PARTS : Cooling Fans : Intel i7 CPU Fans
   Intel Socket 1366 CPU fan
   PARTS : Motherboards : Intel i7 Motherboards
   MSI X58M, DDR3, SLI & Cross Fire, GB LAN, IEEE
   PARTS : Memory : DDR3 Triple Channel memory
   6GB (3x2GB) PC3 8500 DDR3 1066 Triple Channel
   PARTS : Video & TV Cards : PCI-Express Video cards
   ATI Radeon HD 5770 1GB PCI Express 16x dual head, HDMI
   PARTS : Video & TV Cards : TV Tuner & Capture cards
   NONE SELECTED
   PARTS : Hard Drives
   500.0GB Hitachi 7200RPM SATA2, UDMA 300 8m cache
   PARTS : Cooling Fans : Hard Drive Fans
   NONE SELECTED
   PARTS : Hard Drives
   NONE SELECTED
   PARTS : Cooling Fans : Hard Drive Fans
   2nd Hard drive Fan NONE SELECTED
   PARTS : CD/DVD/R/RW Drives : DVD Recorders
   Lite On 22x DVD Recorder Dual Layer +R/RW -R/RW
   PARTS : CD/DVD/R/RW Drives : DVD Recorders
   NONE SELECTED
   PARTS : Media Card Readers
   NONE SELECTED
   PARTS : Sound Cards
   Realtek HD digital audio (onboard)
   PARTS : Modems
   NONE SELECTED
   PARTS : Networking : Network Cards
   Ethernet network adapter (onboard)
   PARTS : Controller Cards
   USB 2.0 Adapter Card 4 port PCI
   PARTS : Cases / Power Supplies : Cases
   Cooler Master Elite 310 black, Side Window, front USB
   PARTS : Cooling Fans : Case Fans
   Dual Case Fans 80 mm DC fan (two fans)
   PARTS : Cooling Fans : Power Supply
   Ultra LSP 750W ATX Power Supply, SLI & X-fire ready
   PARTS : Keyboards
   NONE SELECTED
   PARTS : Mice
   NONE SELECTED
   PARTS : Speakers
   NONE SELECTED
   SOFTWARE : Operating Systems
   Microsoft Windows 7 Home Premium 64bit DVD
   SOFTWARE : Office Software
   NONE SELECTED
   PARTS : Monitors
   NONE SELECTED
   PARTS : Assembly and Test
   Standard assembly and test 3-5 business days