Best bang for the buck is probably the chevy front with rerar drums. I do not even run a power brake booster of any knid. It stops well with 33's. In low of the NP435 and low of the xfer case it can be a little hard to stop, but I have a clutch so it coesn't matter, but with your auto you may want to ask soemone else.
Every thing else you spend over and above the chevy conversion is just that, more money, for progressively less stopping factor. Yea the hydroboost will stop on a dime but the non power assit chevy conversion discs with drum brakes on the rear will stop good. Add a vacuum assit and you probably have all the stopping power you need. Dics on the rear are good but it is a lot of money and time to get it all working well with an emergency brake.
How much do you want to spend to stop a little better?
If money (and time) were no object I would have a hydroboost and rear disc,(it was my original plan) but I bet the first set of pads on the rear would be the last set I ever put on. The front does all the work. I really doubt I will ever need to change the rear drum brakes either. I just decided that it stopped so well as it is I would live with what I have. I like having fewer things to go wrong particulaly with brakes.
A trailer can be fun, brakes or no brakes. Just be careful of the tongue weight.