Good evening Jen... You certainly are in good company as the credentials of those who responded are top flight.
I agree that 4over is an exceptional trade printer but I would also recommend taking a look at the reseller/partnership program that Vistaprint offers. A good friend and old colleague of mine just landed with them and I'd be happy to give you his information offline if you'd like.
I was the original founder of 48HourPrint.com and led the company as its CEO and Chairman to maturity and its peak of success (as of today anyway). We had an amazing team, a great model and for years we literally owned the online printing market (as Vistaprint was nice enough to share).
Long before the term 'web-to-print' surfaced, we defined (and refined) a new manufacturing process that maximized efficiency and all but eliminated the waste that offset printing was notorious for. This, combined with the instant delivery model that the internet provided along with some very forward thinking technology, helped us brake records by achieving gross profit margins that approached 88% (for some products).
I successfully exited in 2008 and my timing was impeccable as the market has been in decline ever since. I'm not mentioning our achievements solely because of pride and besides, option is just that. But I believe any real success will be difficult in an overly saturated market that's rapidly shrinking unless you can invigorate buyers with some new, killer print-collateral products.
The print buying landscape has forever been changed as very few, if any of this year's graduating seniors (tomorrow's entrepreneurs) are even thinking about needing business cards. Instead, I challenge anyone entering the space to go back to the drawing board and put in the hands of those seniors ___________ (insert newly conceived, 'must-have' print item here).
Me? I bought a boat.. (j/k).
William Wallace Mead