Rossi, commercially available Telestick comes in one size, 8 feet, so I'd guess that's a good length. http://www.thetelestick.com/content.html?page=seeit
As you can see in Jamesj's pictures above, my lurk is only about six feet long, too short I guess. I don't remember how I decided on that length, Probably determined by the length of the piece of Bamboo I had to work with. It quickly developed a lot of cracks when I used it, hence the duct tape which fixed it up better than new.
MastersRacer, those pictures were taken several years ago chasing fast skiers on a cold day. I much prefer to Teleboard solo on a warm day. Being able to set my own pace seems to be an important factor for me to successfully Teleboard but you can't go too
slow. Like riding a bicycle, you need some speed before it will work, about 10mph minimum. I took it on the bunny hill for several runs before I got it carving. You can't skid easily, every turn should be carved. Carving on a Teleboard is easier than carving on skis or snowboard but skarving or skidding is more difficult. It will bend and carve a pretty tight turn though once you learn to trust it.
The conditions/speed/terrain that day at Blue Knob were too much for me and I did not have fun, but I've had some really fun runs on the Teleboard when the conditions were right. Groomers out west can be very carveable, but around here cold almost always means firm/icy which makes carving on any gear beyond my ability.