None of the Walmart Everstarts meet the crank requirements for an Opti and accessories. Their largest one, a 29 series (which is the same size and capacity as a 31 series) is a deep cycle battery, and wont work for cranking. It is good for the troller, and very popular. You need at least 950 ccas to allow for engine and accessories. If you want a flooded Deka, then your best bet is a commercial 31 series. It was actually Sherm who introduced me to the idea of a commercial/truck battery for cranking a few years ago. The commercial Dekas would be the 1231 or 1131, both of which would work, with the former a little stronger. You can buy the 1131 re-labelled at Sams Club for 99 dollars. It is also re-labelled for Batteries Plus, OReillys, and Advance Auto Parts. Although it sounds like you want stay away from Interstate, but, it is the 31 XHD for their flooded commercial 31 series battery. If you want AGM, then you have lots of choices. The Northstar/Batteries PlusX2 and Odyssey are both beasts but require a really good charger. Not all AGM chargers will work properly with those two. If you have the MK PC that BCB now uses, you would be fine with any AGM.