I have owned 4 different brands, all triple blank, since putting them in my boats. I currently have a duel pro and it is a good unit. But prob the best one I owned for the price was a Bass Pro Extreem, yep a Bass Pro Extreem. It did a great job... was completely sealed, mounted easily, had charge indicators and had the longest life (still working in a boat I sold 7 years ago). I also had a Cabela's that did pretty well. It was a little smaller (lighter) and easier to mount (a 5 amp per blank system), which is what I had in the Allison due to the size and weight.
As far as amp. advise, I would not recommend one higher than 15 amp per blank, because you will shorten the life of your batteries, w/10 amp per blank being my recommendation. 5 amp. per blank mods are cheaper, tend to be a little smaller, but take longer to charge. Just make sure the mod. you choose has auto shut off in order not to overcharge and burn your batteries and/or over heat. Also mount it where it can breath to prevent overheating and fire hazards. If you get a vented water resistant mod, consider putting it in a side box where it will not get water on it and make sure you don't crowd the unit.