FWIW, the Trac Lok isn't much cheaper than the TruTrac, but if you're in Canadia it might be different. In US dollars, I can tell you that the TracLok for a D35 is about $420, and the TT is about 470. (Was $370 juast a few years ago...) TT is a much better LSD for not a lot more money.
Also, putting a LSD in the rear diff is not nearly as expensive as doing a full gear setup... Pinion depth doesn't change when you put in a new carrier, so you're only talking carrier shims to set lash. I have had good luck so far just swapping the shims from the old carrier to the new and re-installing with new bearings. backlash came out in spec on both diffs I did that to, and they're still going strong ~90k miles later.
FWIW, you have traction control, and it'll do a fairly good job of keeping you mobile if you learn to use it. A single press of the button should turn off the engine power reductions, but leave brake control active. This way, when one tire spins, traction control will apply brake to the spinning tire to get you moving again. You just have to be steady with the throttle, and give it a second to build pressure. It should become more agressive in low range, particularly in the lower gears, so that you can keep going even with tires in the air. While a LSD does add some capability through ease of operation, your traction control system is probably worth more in the long run.