Hello mush, as far as I'm aware, the "pit buddy" is the only one of its kind. Most people tend to make their own, a couple of quid for a bit of ply, carry strap is sold by the meter at b&q for pence, an old truggy wheel screwed down for the fuel bottle to sit in, and those springy tool clips from machine mart for yer glow stick/plug wrench etc.
So, nigh on £30 for a pit buddy doesn't seem all that a good idea now eh.
Hope to have been of some help