Joe,
The best battery i have found for a cranking battery / electronics battery would be The Energizer, i have had it for 3 years and no issues (yet). Do not use a deep cycle for cranking, I use a dual purpose for cranking and run all my electronics off that battery. I also found the AC Delco batteries in a group 31 were the best trolling / deep cycle batteries for my 24 volt system. If weight is an issue go with a group 27. Remember to always get a marine grade battery no matter which you buy, they are designed differently than standard automotive batteries and will take the pounding on the water better.
Also, look for the free replacement guarantee, the longer the better. 18 months for the AC Delco, and most Sears Die hard marine batteries, 12 Months on the Wal-mart Brand and 18 months on the Wal-Mart Maxx Brand.
Also, IMHO Interstate batteries, which came with my boat(s)....aren't worth the plastic they are made with, they lasted for about 1 season and then would die 1/2 way through the day on a 24 volt system.
Eric
