Please, I have a V8 R34 S14 D1-Spec Rotary VTEC RB23 RX9 drift car with a 4.5 speed gearbox. Mine was also imported by Edward Lees. I must say he is a top bloke. He assured me about the specs of my drift car were accurate.
Also avoid eBay spec plenums. Avoid eBay spec anything that's a critical component of the car. Stick to eBay for silly shit like gear knobs, bulbs and stickers.
Ring some places and get some quotes. Someone will do a quality job for a reasonable price.
You could probably do better with some PVC pipe from Bunnings.
Seriously though, if you're getting a manifold, get a good one. It's not worth the issues that you'll come across down the road. Get a proper brand one.