Domain Searching

I have this client who wants this on his website. But he wants the option to allow people to check and see if a .net .org .tv (etc..) is registered or not, and if it is (or even if its not) return lots of alternate options which are NOT registered as well. The best example of this is enoms search at: http://www.enom.com/domains/Register.asp (do a search, that is exactly what he wants, he even mentioned enom and showed me that page). How can this be done? Ive been looking around its all in asp but i want it in php, is this tough to accomplish or easy but just looks like alot.

You would have to have access to the ICANN DNS servers. There is no way to just randomly search the web or something for this type of information. A domain could be registered, but no website could be tied to it and there's no way you'd know other than having access to that table.