Samsung phone for T-Zone

I'm on a grandfathered data plan called T-Zone or TMobileWeb.  I pay $6/mo. and I'm NOT looking into upgrading to another more expensive plan.  My question is, what is the best Samsung smartphone that I can get without having to change my data plan?  It can be an old or current phone.  I'm looking for a touchscreen though as my old T-Mobile Dash 3G's keypad is getting old for me.  I'm also looking for one with an above average camera and web-browser.  Any ideas?

Most Samsung smartphones are blocked by T-mobile from T-zones.  The Behold 2 slipped through the cracks and was usable, but it's very dated.

There have recent reports of the Gravity Smart being able to use T-zones.  See post 3794 in this thread on Howard Forums:

http://www.howardforums.com/showthread.php/1491386-Grandfathered-5.99-T-Zones-Data-Discuss-All-Related-Questions-Here-ONLY/page253

The thread is dedicated to what devices will work on t-zones.