endlesssummer, If you're not in a time constraint, my one piece of advice would be to take your time. A longboard is a big purchase and you'll definitely benefit from looking around a bit.
Take day trips around to as many different shops as you can and pull boards off the rack--if they let you. Ask questions to the people who work there. Talk to local shapers and tell them what you're interested in. All the while, keep an eye on craigslist and don't be afraid to check out yard sales.
After a while, you'll probably get a feel for what you're looking for and where/whom you want to get it from and you can feel better about making your decision then.
Whatever you do, enjoy the ride my friend.
Oh, and congratulations on graduating college too!