a few lessons learned from my own book of towing...
--what the dealer says you can pull is bunk! I didn't get 100 miles pulling my TT before the 10 bolt rear end blew up.
-- There's a relationship between trailer length and tow vehicle length & the friction anti-sway isn't the cure-all. Carefull how long a trailer you select. (even with a suburban!)
-- once u get it moving, you need to stop it! How 'beefy' are the brakes on the blazer? any way to upgrade them? (changing to 14FF fixed this issue and some of the weight issues too for me)
-- Don't rely on the documentation for hitch weight (which is normally a dry weight. Things like propane, batteries & water add up quick, let alone the beer & ice!)
-- Spend the $10 and weigh your truck. Do it again with the trailer and actually SEE where you weight goes!
-- Not sure if your blazer is auto or manual, but get a cooler if it's an auto.
-- What tires are on the sub? LT? load range? (i ended up on "E"s to avoid any problems)
not sure if you'd thought of some of these.. but wanted to share the pain i had along the way!

good luck! having a hotel behind you is great sometimes!