[camaraderie]

Fret...welcome to the light! Have you looked at the bluewater boat list here:
http://www.sailnet.com/forums/buying-boat/39936-updated-offshore-cruising-boat-list-january-2008-a.html#post251474 and the additions two posts below?
None of the boats you mention are on either list even though there are a number of relatively inexpensive boats in your size range.
Not to say you couldn't make a passage in one...but they are not built for extended bluewater cruising.
I also think that you will find yourself in the $40k range on any bluewater vessel of this size by the time you get one ready for sea, equipped and all systems in good condition.
Let's hear a bit more about your actual plans and experience.

 

[camaraderie]

Any of the boats you list are perfectly capable of cruising LIS and the Northeast. Given the ages...the best advice one can give is to pick the one in the best cared for condition...after getting a survey. If they were all in great shape, I'd go with the Tartan30 myself.