AC Advice. Need a new AC line.

I had my AC checked a year ago and it was determined that I need a new AC line (Pipe-Front Cooler, High) is the part name.

I have 2 questions:

1. My AC has not worker for about a year - do you think that I will have more problems ex: seals, switches, etc. because it has not been operating for over a year? (I know it has to be charged again)

2. I have a small pin hole in my heater core. Will this affect my AC (will my AC loose charge)


HERE IS A LINK TO THE PART I NEED!
http://www.courtesyparts.com/fronti...c-condensor-dryer/-c-2129_2130_2168_2189.html