Streaming BD rips, hard wired or usb to router or NAS? Thank you

Hey guys, I was wondering what would be one of the best ways to stream high bitrate bluray rips over my network.

My router is a Netgear WNDR3700. I usually stream my content from a computer in my room connected to the router through the 5ghz band. My computer has a gigabit ethernet port. I really should have it hard wired...

I have this 3tb Seagate GoFlex external hard drive that I could connect to the usb port on the back of the router, but would I still get the same problems? I have this pretty old computer that I could theoretically setup as a NAS, but I am wondering if it is too weak?

It has:
300W power supply
AMD Athlon 64 3500+
2 GB Ram

Is that good enough for a NAS and what about power consumption? Did you guys experience your electric bill increasing once you had your NAS set up and running all day?

Sorry for all the questions guys, and I'd like to thank you before hand!

When you say "the same problems" what problems would that be?

N wireless should be OK to stream HD content, as long as the connection is not bad. Wireless across a few rooms may not be too good for HD streaming.

NAS over the network will work fine for that, power use will be less than leaving a light bulb on all day.