Gel is a total waste of money, its a poor charging and over expensive, it had one major trick the ability to be used upside down, now they say dont do that anymore so now its only plus point is non spill in event of a split case, how many times have you seen or caused a split battery case? none?
Hence its seems a bit pointless buying an expensive battery with no advantage for you and several disadvantages
1. Needs special Charger
2. Charges slowly (as to be charged at lower rate)
AGM (absorbed Glass Mat) is a far better battery than Gel, but again expensive, you gotta ask yourself are those advantages useful to me? ie have you ever cracked a normal battery and now feel the need for a mega expensive it dont matter if I crack it battery? No? read on
A standard lead acid (same as under the hood for starter) they are cheap able to withstand shocks of the road, unless you need any of the AGM's tricks you will get just as good a service from a normal lead acid battery, sure go for a proper deep cycle, more lead = longer life
Sonet, I am not sure where 1lb per Amp hour came from, is it a typo?, perhaps the most famous deep cycle battery the Trojan 105 is a 225 Ah battery according to your post it should weigh nearly 225 lbs, in reality its 62 Lbs
http://www.trojanbattery.com/Products/P ... Name=T-105