Toytec.
I got 4 from Wheeler's and the shipping was $13 from Oregon to Alabama. I was going to purchase them from Toytec and at the time was only going to buy 2 and the trim packers were going to be $20 and the shipping was going to be $18 from Colorado to Alabama. This seemed crazy to me since trim packers don't weigh anything and could be sent in a small package. I really like Toytec and I purchased my springs from them but their shipping charges are a little steep.
I was looking around for some info on Trim Packers and saw your post. I was curious if you could tell a big difference when you put them on. I am debating putting a pair on my rear springs to fix the little bit of saggy butt.
I would think it depends on how much sag there is. .5"-1" maybe 2 at the most. Two OME packers should be .75" Anything more than that I would get new springs.