I wouldn't go overboard on a light toad. Remember that you will be riding and driving it-------often in unfamiliar areas. Your safety and comfort should be a factor also.
I pull a 5000 lb. toad because it was what I had that was towable when I bought the MH. We had the occasion to climb the Wolf Creek Pass (10,800') east bound two days in a row (long story). The second time, I elected to unhook the toad and have my wife follow me. While I was able to climb it a little faster, the difference wasn't great-----still ended up in 1st gear at times.
The difference between towing an 1800 lb toad and a 2500-3000 lb toad will be even less noticeable. The difference in comfort and safety (and resale) will be much more noticeable with the heavier vehicle.