Group 27/29/31's will fit w/ the tray installed; just pay attention to the height of those studs. Take a look at the Trojan 31XHS and T1275's which are classic 12V wet cells that add quite a bit of AH capacity compared to the above but require the removal of the slider.
The popular Trojan 105/125 6V options are a bit tight on the height limit, which is why there are a few on this group moving to an AGM option, specifically the Lifeline 6V-4CT or 6V-6CT, which again yield more capacity, but will be installed on their side rather than vertically. Get your wallet out though.
Personally, I got a great deal on new GRP 27's locally, so that's what I'm running now. My next set up will be the Lifeline 6CT or Trojan 1275 option; as when paired, each give 300 AH of capacity @ 12V. good luck.
BBF