Fenlander, you're quite right we did cobble together a bow dolly/transom wheel combo, which worked well. However for regular use felt uneasy of the stresses exerted on the bow fitting with the force of dragging a heavy rig over dunes and soft sand. We could also leave our boat inflated on the launch trolley over the season, which suited us best.
If reasonably flat/smooth terrain then the bow dolly/transom wheels combo is a great solution. Very impressed with your fancy Trem set. We spent ages, unsuccessfully, trying to source a set of the Zodiac/Bombard ones.
Dave, if you're after a set of robust transom wheels, then the Trem heavy duty ones are very highly rated. Personally, the best set I've seen are some Russian copies of the Seamax ones. Very strong with a huge fixing bracket able to effectively spread the twisting/pull out loads on the transom. Only drawback is they come with small wheels so worth replacing with a pair of 16" dia. foam filled ones.