opening a can of worms . . . .
I would start by figuring out what kind of charging system you have, and what you are willing to spring for. I went with a good old Marine Deep Cycle FLA (Duracell). I got it on sale at Batteries Plus so I ended up with 105AH for about $100. Now with an FLA you will lose cycles if you take it down below 50%, but you can still hammer it down to 80% DOD for 2-400 cycles. In actual use, I almost never get below 50%, so it will probably be many, many years before I get 3-400 nights camping out of that truck. i.e., unless you're full timing, the number of cycles is probably not a real concern.
My bigger concern is not the battery, but how to get the charge back in it when I have used it. A good charging system, well matched to the battery, will keep the battery happy and extend your usable capacity. A little solar goes a long way in reducing the depth of discharge you see, and a good onboard charging system (my old Toyota is crying out for a Redarc or CTEK), will drastically shorten the run times required to put amps back in with the motor.
I posted what kind of charging system I have. I have a Blue Sea ACR. I have shore charging every night, and solar when don't have shore charging.
If you get the charging system right, you may be just as happy with a $100 battery as a $400 battery. If you don't get the charging system right, then that $400 battery may not last any longer than that $100 battery. A prime example for me is the Odyssey. No doubt they are one of the finest lead acid batteries out there, but to get that performance out of them, they want to be charged at 14.7v. (source
https://www.odysseybattery.com/documents/US-ODY-TM-002_1214.pdf) If you lower that to 14.2v (which Odyssey describes as the typical automotive charge voltage), you reduce the life of the battery at 80% DOD from 400 cycles to 150. i.e its starts to perform just like (or even worse than) my $100 FLA.
My charging system works just fine for what it's supposed to do. The House battery is used only for starting and stock items, no aftermarket electronics are connected to the House battery.
My Landcruiser charges at about 13.3 and lower. That would be awful for an Odyssey. Without help for the charging system, it doesn't matter what I buy. With some help on the charging system, I can get by with almost anything. If it weren't for some parking deck issues, I could have everything I want with a roof mounted panel. Likewise, in my situation, I would be much better off with a CTEK D250 ($239 at Amazon) and a $100 Group 31 FLA, than I would be dropping a $400 high end AGM in without any other changes to make it work. My charging system just won't take advantage of it. As things stand, I am probably going to cannibalize a Redarc 1225 from an unsuspecting Turtleback.
Of course once you have invested in a better charging system, you may start wanting (as opposed to needing) a better battery to take full advantage of it. One of the most attractive features to me of Lithiums and premium AGMs like Odyssey and Lifeline is that they recharge very quickly. (Fast charge on a typical FLA is about 0.2C, Odyssey advertises up to 3.1C, Lifeline advertises 2.5C). A fast recharge is more important to me that overall storage capacity. All AGM's will give you faster charge than FLA, spill resistance, better shelf life, lower internal resistance etc... They really do have a lot of advantages. So I may face new temptations soon . . . .