Joe, this should help you if you can find it in your tropical southern climate... Sno-Seal: Waterproofing New Hiking Boots | Section Hiker
You smear it on and then melt it into the leather with a hair dryer. I spend 7 months a year in slush and wet and this is the best I've found. Been using it since the late 70's. Tried other things, nothing touches it.
I'm enjoying this thread because it just saved me $90. I was seriously considering buying some ariat terrains but my sneakers will do for the nice weather.
I just have to spring for some half chaps now. Never used to bother me but the last few rides as my mileage has increased my calfs have taken a beating. Guess I'm just not 17 and indestructible anymore.