I have a yellow top optima agm in my Yukon right now. I had a dual battery system in a jeep with 2 yellow tops. They are a great battery. The one that is in the Yukon was used in our camper for several years, then sat in the basement unused for a few more years until a month or so ago when I finally put it in the Yukon. I would charge it whenever I would think to, usually about every 3 to 6 months, and it was amazing how it held the charge that long. It would never be below 12v.
If you have a Sams club in your area, they have Duracell agm batteries at a better price than the optima, and in my experience perform just as well. I had one in the Yukon until I moved it to the pacifica recently, one in the T&C, and two deep cycle Duracell agm in our camper. No more corroded cables or trays because they vent barely any hydrogen gas compared to a wet cell battery, they hold a charge much longer, and they last longer. The two in the camper I have mounted sideways. The Yukon is not a daily driver, it is just for towing a camper, so it sometimes sits for several weeks. Also it is not driven in winter. I just put a charger on it every 6 to 8 weeks or so to top it off. I have never found it flat as I had with the previous wet cell.
So, I say go for it after you fix the draw issue. Also, it sounds like you need a high output alternator to keep the battery charged up. Drawing a battery down past 50% charge will shorten its life significantly. I would look for an alternator that can supply at least 105 amps at idle, and your battery should last much longer.
