Reason MC batteries come dry and car are wet as they are delivered differently. MC batteries come via UPS, car come via freight. They can't ship a battery with acid in it as it is a safety hazard. Reason why AGM can be shipped is that if they crack they don't leak, the acid is absorbed into the mat that is laid on the lead plate. Easiest way is to call a batteries plus or walmart etc. in your area, pay prior to picking it up, and ask them to fill and charge it prior to picking it up. When I worked at batteries plus we did this all the time. Also, the acid that comes with most batteries (in my experience, mainly yuasa, champion and B & B) is premixed, you just add it to the top line, let it bubble out, then top it back up. Make sure all the cells are level prior to charging. From there on out you just top it up to the top fill line w/ distilled water.
You can buy AGM batteries, but they don't always sell them for our bikes, You can also buy maintenance free MC batteries, but you still need to fill them. Its easy as each cell has a premeasured acid pack that you fill it with, but again, I don't think they make them in our sizes.