Ping-pong phy solution provide 2 controllers with 2 separate Avalon port. The advantage of ping pong compare to 2 independent controller+interface is it will same some add/cmd pins.
It is hard to say the comparison between ping-pong memory over normal (single) interface with shared CKE/CS//ODT. Because the former give 2 user port solutions while second one give only one.
For all voltage that you need supply to FPGA, you can refer to quartus compilation fitter report. Go to pin-out file and you can see every voltage that you need to connect to every FPGA pins.
Hope this helps.