Don - I'll add another recomendation for Legendary Trailers (410-349-3611) - Chris and Dustin have done work on my trailer before - always top shelf service. If you can swing the cost - convert to disc brakes. Much simpler system, easier to wash off, and seem to last much longer without major maintencance than drums. I converted mine about 4 years ago - clean them up every spring and no problems. "Wash down" systems wouldn't be needed since all components are exposed. I'm not convinced that a wash down system would do any better on drum brakes either. Unless you can wash them off right at the ramp - both after you launch the boat and right after you pull the boat - the salt is going to dry and start eating into things by the time you get home. I still spray everything off when I get home, of course - but some damage is done each trip anyway -- just the cost of boating in salt water.
I have Kodiaks. Most people will tell you they are better than Tie Downs. Ties Downs have a bad reputation, particularly with regards to customer service. Eastern Marine in DE has good prices and are very knowledgeable, although they were not particularly friendly, at least to me. If you go to the Hulltruth you can read about trailer brakes for an entire day. Kodiak makes several levels with the stainless having the best reputation and also being the most expensive.
Legendary Trailers did mine in May and I was extremely pleased with the service. They came out and inspected, gave me a written quote, and then scheduled a day that the would be out to do the work. Very professional!
Another vote for Legendary Trailer. They came out and replaced my old drum brakes with Kodiak stainless steel disc brakes, installed a tie Down disc brake actuator, repacked bearings. They did the work during the week so I did not miss any weekend boating time. I have the washdown system on my trailer, but that is only good if you are anal about rinsing every single time. There are days that for whatever reason, I just am not able to rinse. That is one reason I switched to the stainless steel.
Went to re-pack the bearings in my TieDowns disc brakes last year and found the the pistons were corroded to the point where they were getting stuck in the out position. Although they didn't look too bad, they weren't traveling inside the piston the way they should. This resulted in a lot of heat being generated during hauling as the brake pads rode the discs after being pushed out by the actuator.
Did some research and decided to change everything (bracket, calipers, rotors) over to a heavier duty Kodiak system. Got everything I needed from Dave's in Glen Burnie and did the job in the boat yard with no special tools. Other than the grease mess, I can't say that it was too bad. Bleeding the system was no issue either.
Now my hubs are only slightly warm to the touch, and make virtually no noise going down the road.
So I'd say change your drums to discs if you can swing it. Also, when you get your new brakes, get into the habit of depressurizing your trailer's brake system whenever you park your boat. Do this by pulling forward a foot or two before unhitching. The idea here is to get the actuator to extend out as far as it will go so that you don't have any fluid pressure in the lines. The non-pressurized system should allow the pistons to retract into the caliper housing so as to help minimize corrosion during storage.
They guys at Dave's told me this little trick and it seems to make sense and is simple to do.
Anyway, good luck with your brake of overhaul. You'll be glad when you do it.