Wanted to put out my quick findings with the 750ti since I went through a build and learned a bit, hopefully this helps some people.

• EVGA Ftw edition, currently running 320khs for each, 5x cards
• Gigabyte UD3 motherboard, some random 4gb stick of Kingston ram that was cheap on amazon
• I was unable able to get the USB 1x-16x risers to work.  Performance was all over the place, and I got random crashes and instability in Cudaminer.  These same USB risers are now used on a r9 270 rig at 100% speed, so I just switched risers with that machine -see next note
• I was able to get a mix of unpowered ribbon 1x-16x mixed in with powered 1x-16x risers to work just fine at 100% speed.
• I can not overclock memory more then 600mhz
• GPU doesn't have much of an impact on the hashrate
• x86 miner is faster than the x64
• Cudaminer 750ti Settings I saw that work / made a difference:  T10x24 performed slightly better then T5x24  and -H 2 is the best for stability.
• Windows 7 64bit, really wish there was a BAMT equiv for cudaminer though.
• Inside a heated home the 750's do not break 50-55c at full load and overclocked

I do get random OS reboots, but I set my windows build to auto login with the miner spinning up on startup. So a crash or 2 a day doesn't impact my mining for more then 5 minutes.  Still not sure what that is all about...