First build questions!

So I have a 1981 gs850g, and I’m planning on stripping it down to the frame, painting, re-gasketing, the whole 9 yards.That being said, I’d like to switch to the pod filters (yes Im aware of the performance risks) and eliminate the air box as well as move the battery so there’s that nice classic cafe “window” in the bike.I plan to weld a drop pan under the seat to store a battery there instead, but I’m having issues finding a smaller battery to get the dimensions planned out.Does anybody have a small sized battery they would recommend for this type of build? I’ve seen them on YouTube builds from some popular channels but getting the information out of them is pretty much impossible.(The bike doesn’t have a kick start) via /r/CafeRacers https://www.reddit.com/r/CafeRacers/comments/aqxhq5/first_build_questions/?utm_source=ifttt