Well heck.
My old SLA (flooded) made in china battery I got from a local outfit lasted about 6 years with consistent tender use, then shorted with a snap.
When it died I replaced it pretty much the same as everyone else says. A dry cell (when purchased) YUASA AGM. I get 'em from YUASA off Amazon.
Never had a problem with 'em oldest one I have right now is a couple years old. It replaced a one year old generic AGM that spent at least part of it's life off a tender. Same with the ~1 year old one.
Getting the dry battery is a good thing. You do have to add the acid (be careful), let it sit for an hour or two (really..let it sit before charging) then charge it (read directions) at ~1-2amps or less depending on battery, but you will have an absolutely fresh battery when you install it.
Far as more CCA goes. more CCA (or CA etc) is better, but fitting it in your allotted battery space is even better. Personally I've just stuck with the factory/YUASA recommended sizes.
No real problems, & I didn't have to spend time with spec sheets looking at battery dimensions.
If you do go with one of the cheap outfits (~1/2 the cost) read the reviews, & make sure they have a good rep for honoring their warranty. They will usually send a wet battery, which could have been on the shelf for who knows how long, from a company that's all about cost. You very honestly could (and eventually will) get an acceptable battery, but you may end up using the warranty a couple times. Those outfits realize this and it's built into the price..double check who pays shipping on warranty.
Or ya could do what I did with my recently popped SLA & use a reputable local outfit (read their warranty some outfits give ya nothing on bike batteries). Drawback there is it cost about the same as the YUASA AGM, but I did need it that day. No real complaints..6 years on a motorcycle battery is actually pretty good.
