RacerX is the new kid on the block, but seems to know his stuff. Suncoast has been around forever and has a good rep.
The Suncoast kits will cost $495 for the basic clutch kit plus another $337 for the coast clutch kit for a total of $832 not counting the torque converter. Does it also include the valve body? Torque converters cost anywhere from $200 to $1,000, and I would go with a Precision Industries Stallion 13" PowerStroke converter at the high end of the price scale - because that's the one that is included in a BTS rebuild.
Precision Industries - Stallion Power