What you need is a freight consolidator. But two paintings is a mighty small amount of freight for people like this.
You might try these guys- havent used them, but they are the type of business you would want-
http://www.econocaribe.com/cgi-bin/NewsD.pl?N20030915.txt
I think your best bet, however, would be to have the paintings unframed, rolled up, and shipped fed-ex or DHL in a tube, then have them restretched and framed here- framing in BA is quite reasonable compared to the USA.
Even better- put em in a tube, and check em as luggage. I have brought down tubes 7' long with rolled up artwork in them, checked, no extra charge, no hassles at customs. Not a word, at customs, in fact.