NEWBIE.. HELP Blu Ray/Wii Installation

[fabulosity]

Hey guys!!

HELP! I have a professionally mounted LCD 46" JVC TV in my living room. All the wires are inside the wall and they made a little plug behind it to. When it was mounted; it was just attached to the cable box and the DVD player.. (I know really nothing about this kind of stuff).. however the guy who mounted it sold me a "monster" cable for $115 in addition to the mounting. I know I got ripped.. so I am trying to be proactive this time. Now I have a new Blue Ray player.. Sony S550 that I need to be integrated, as well as a Wii. We have the Wii in the office now as that is the only TV where the inputs were exposed (all of our TV's are mounted). My fiancee knows less about this stuff than I do.. so theres no help there. We want to put the Wii and the BR player on the JVC.

What cables do I need to buy? I know the BR's need an HDMI cable.. can I use the one that I have from the DVD player..but I'm thinking maybe the "monster" cable is attached to the cable box for HD.. What's the best cable I should get? I found a place HDPI.us that has pretty cheap cables. Are these legit? Do I have to get another cable for the Wii or can they ones it came with work? They were only 3 bucks on this site so I was going to get a 3ft one..just in case the other one wasn't long enough.

Guys I'm such a newbie. Please help me.. And I apologize for all of the questions. Please offer any suggestions too.. that would make our viewing better. I just get mad that I can't do this stuff myself.. We're paying $105 for someone to come out to do this because we don't want to reck the tv or damage it because its mounted. But I'll be darned if they get me for some more money that I don't have to spend; which is why I want to have all the cables already.

Thanks guys!