Go for the IPS displays. It's a great price, and the difference compared to TN is ridiculous. This u2410 i have now is the first IPS i've ever owned, and i love it. I doubt I'll buy TN ever again.
Samsungs are great monitors, but it's still TN. If you were staying with a single display, I probably wouldn't try so hard to convince you , but since you're going after a multi-monitor setup, GET THE DELLS. Uhh.. i assume they have the VESA mount - all Dells I've seen, do.
You have no real reason to NOT get the Dells.
Be sure to post some pics when you get it all set up.
I've used dell monitors for my last two monitor setups. I love dell monitors. I just got my first IPS a few weeks ago, and I can never go back. TN's just don't have the color I like.