You should be able to find your answer on the FAQ/master thread... if not, you can go to www.sqtalk.com, and there should be some trip reports concerning SQ ultra-long haul service to LAX and EWR on the all J Airbus A340-500s.

Yes, EWR to SIN nonstop flights are operated by an all J Airbus A340-500s.
They have universal power outlets and no need to worry about EmPort.

The seats are arranged in a 1-2-1 arrangement and I guess most people prefer the forward part of the cabin. For sole travelers, the window seats should work best.

Carfield