Help with springs

My truck is a 2009 4dr with towing package. I had the original harsh ride TSB done early on which put 3 leaf springs on my truck.
There was a slight rake to it, and I liked it. Then I had my frame inspected/coated as part of that whole mess. My frame was in good shape so dealer coated it. What I did not expect was that they replaced my springs again under the broken leaf recall, ect. Bottom line is that I have been back to the two leaf setup since. I lost my rake. I have been mulling over solutions for a while, but it was not a priority. I am now contemplating towing a 4500+/- trailer. I know it will sag. So, not being a suspension or lift type, what spring setup would be recomended to get back to the original "harsh ride" TSB setup? This (towing) is more compex than springs, I know. This is just a starting point.
Thank you for your comments/suggestions.

 

An add-a-leaf into the existing pack will strengthen/firm them up, but it will also add lift. Or you can go with a full leaf pack replacement, but they're pretty much all 2" of lift and taller.

 

What is your opinion of the Heliwig bolt on type? Would that be in the category of AAL? I am hesitant to repace the whole pack as i rarely load the truck, and towing the trailer would be sporadic at this point.

 

Tell the dealer they need to put the TSB leaf pack back in, that’s what they took off that’s what should have gone back in.

 

I don't mind the bolt on type, I've seen the demos and I think they're a good option for towing like what you're doing.