Can I register two iPads to one computer?

Yes, there are no problems with using multiple iPads on the same computer - probably best to give them separate names when you connect them for the first time so as to keep their 'identities' separate (apart from anything else it'll make it more obvious to you which one is currently connected).

yes it can sync with 1000's of ipads
and iphones and ipods but a ipad and... can only sync with 1 computer

No problem, iTunes recognizes different devices by their name so make sure that your two iPads have different names. Each one will keep its own settings for what gets synchronized.

You can not connect them both at the same time, as far as I know, but you can synchronize different parts of an iPad (i.e. songs, photos, contacts) to different computers.