I would definitely go with the single i7-5820K processor because with very modest overclocking it will out run a pair of x5650's. I have dug deep into our Premiere Pro BenchMark (PPBM) results and it is very evident to me when I compare the CPU intensive benchmarks. Besides your 32 GB of RAM would only be 2.67 GB per core with the Xeon's and that is less than Eric recommends. Also anytime you need more CPU power in the future there always is the 8-core upgrade available
i agree with bill. its even possible that the normal performance loss from dual cpu's setups, will place the dual xeons below the 5820K even without overclocking. the xeons are also 5 years old, so everything about them from memory speed & bandwidth, to motherboard chipsets, to cpu instructions will be at a disadvantage compared to the new 5820K.
the 32gb of memory with the xeons may not be a problem, i believe eric's recommendation was for after effects. if you plan on using after effects the 5820K may also be a better option, besides the higher memory per core, it has higher clock speed per core, to help overcome AE's performance limitations. they are currently fixing AE, but wont be fully fixed for some time. at that time, the insane memory per core recommendation may be removed.
ok thanks guys, I appreciate the help!