Modchip Questions

[kbb]

Which is the best one? (neokey, neo2,etc.)
How difficult is the installation (Could I do it or should I get an electrician)?
If a chip is installed do games have to be patched?
Where is the best place to purchase the chips in the US? (Do any stores have them or are they just online)?
What is the best site for diagrams?

Thanks for your help!