The limit for a Blazer according to GM is 5,000 lbs max trailer weight, with 480 lbs tongue weight. Nearly all toy haulers, when loaded, are going to be dangerous with a low lift Blazer with 8" it is that much more risky. If you want to go with a 24' trailer, you are going to need to look at light or ultra-light trailers, in order to get the weight to a manageable level. The short wheelbase of the Blazer really cannot be helped much, and it has a major effect on towing.
To give an easy example, Krusty is currently sitting on 2" springs 33's, and my 12' Apache pop-up trailer pushes it around. That trailer loaded weighs in at 2230 lbs, according to the certified scale near my house. A little bit of a cross wind can make it a real handful, and it is only about 3/4 as tall as my Blazer currently. Axles do nothing to increase tow capacity, wheelbase does.
If you insist on doing the toyhauler, consider the dry weight of the trailer, plus the water/other consumables, plus whatever toy/s you plan to haul, and then think about the increased leverage that the long wheelbase of the trailer is going to have against your very short wheelbase Blazer. Toyhaulers could be done, but you are going to have to look at something smaller if you plan to tow it any distance with a Blazer.