The first one you listed from EBAY is the AEM Brute Force intake.
Or at least from the photo it looks exactly like the one I just installed last night on my 2001 Xterra.
I paid about $220 from Summit Racing for mine!
I'm not sure why it's listed so cheap on ebay... Unless what you see in the photo isn't really what you'll get.
It went in fine, no problems. Seems very well made...
So far I only drove it once last night with just the new intake...
The intake sure changes the sound of the engine when you step on it...
I can't say that I definitely feel more power though...
The second one you listed looks like just an air filter that replaces the standard air box. It looks like it bolts directly to the stock MAF sensor pipe. I wonder if it comes with anything to hold everythng in place? It might just flop around at the end of the stock air pipe...