I am using SNAP here with my ATI X850 XT PE card, pretty ancient stuff by today's standards.
...BUT...
It is accelerated (about 10x faster in PM than Panorama 1.09) and will do dual-head display, although, that requires one panel to be VGA driven and the 2nd one to be DVI connected. Specifically here is the key note, given your mention regarding digitally-connected LCD panels:
Please note that there are some restrictions imposed for MultiHead:
1. Only CRT (15-pin VGA) output is supported for MultiHead at this time.
You may need to use DVI->VGA connectors on some graphics cards. The
only exception to this is the ATI Radeon chipsets, which can also do
multihead in CRT+DFP configurations, due to native panel programming.
CRT+LCD, CRT+TV, and DFP+DFP are all unsupported at this time.
Not sure about the ATI HD stuff, however the readme does show the following 7xxx series cards as being supported: ATI Radeon 7000, Radeon 7200, Radeon 7500