Most of the gliding clubs want you to be an active glider pilot as well so you at least have some understanding what it's like at the other end of the rope - it does make a difference.
In terms of tailwheel time, it's about teaching you to use the rudder and fly properly. What you fly doesn't matter so much, but some of the taildraggers are more of a handful than others. A Citabria and Pawnee are dead easy. The Lightwing, Skyfox, C170 and Auster are about the middle of the road. A C180 Pitts or CAP10 while not hard, takes a little more effort than than the other types, especially if you've never flown anything bigger than a C170.
While the Ultralight time doesn't count towards a CPL it will teach you to use a rudder. If there's a tailwheel ultralight near your home it wouldn't hurt to get a few hours on that at a much cheaper rate before jumping in to something bigger. You can actually count the hours if you go through to the stage of getting a Pilot Certificate.
Curtis Aviation do a good tailwheel endorsement. They also have a C180 you can hire with an instructor. You could do it all in the C180 to feel right at home, or start off in the Citabria then move to the C180. Usually can knock it all off in two days. I believe Phil Unicomb is floating around your area and used to do tailwheel endorsements and emergency maneuver training in the Pitts. He was out of the air for a while after an accident last year, but flying again now? Another good albeit more expensive option.
The tailwheels tend to be easier with a glider on the back as the glider keeps the aircraft straight by pulling your tail. You have to remember who's paying for the flight time though - immediately became obvious who the good tow pilots were and who the crap ones were. It is NOT a good way to build hours when you're looking at 2.5 minutes per tow, but is good fun flying and quick 'circuits'
