swaping ac unit. Help!

My 2 cents worth, get an aftermarket kit that has everything and it will be easier, more efficient in it's cooling abilities, easier to find parts in the future and possibly even cheaper by the time you are done. The kits that are out there, at least some of them, are designed to install in cars w/o a/c.
If you conduct a search you should find several threads similar to your questions. My 2 cents comes from following some of those threads, never having installed mine yet...
And yes, welcome aboard - glad to have you here.:cheers:
C