Welcome to the forums! I just took a look at the links you posted... If your ultimate goal is to race in regattas and be competitive, your going to want a newer boat.
The newer boats have several nice features that those older boats are not going to have. The 2008 boat will have newer and better sails (newer sails are going to make a big difference), one piece rudder gudgeons, better rudders (probably EPO 2's), integrated travelers, Aussie jib halyard, a mesh tramp, low profile mainsheet blocks and adjustable rudder rake castings. Not to mention that 2008 boat is going to be the lightest of the three.
If the 2008 boat is within your budget, get it. Its actually seems like a pretty good deal and there might be room to negotiate. I just looked in the Hobie catalog, and a new complete mast assembly is $1743.00. What you'll need to find out is whether or not they still have all the rigging. (shrouds, fore stay, trapeze wires) If not that would add a bit more. You could also probably find a second hand mast if you wanted to try. You'll be able to find a trailer pretty easily and cheap - I see trailers on Craig's list all the time for a few hundred bucks. It might be a little more money than you had intended to spend, but I think you'll be happy you did. Especially when you start attending regattas.
Another thing I would say, is focus on the quality of the boat and don't be swayed buy the accessories...
If the budget is a little more tight, I would avoid the first boat. Just my opinion... I would avoid a boat thats been re-gelcoated and currently has anti-fouling on it.
As for the second boat, it looks good, just be aware that he says he purchased an extra sail, not a new sail.
Good luck! Let us know what you decide.
PS: Where are you located?