AGM battery, now what?

Hello all,

Last year I bought a deep cycle AGM marine battery (105@20Ah) to power my CPAP machine when I am camping. Now I am buying a house and will finally have room to eco-hack, etc.

So, my febrile geek brain has been atwitter wondering what I might do with said battery+panel+charge controller. I have an Ansmann 120VAC/12VDC input smart charger for AAA/AA/C/D NiMH/NiCad/Li-ion batts. So, one obvious application, given the charger's tender function, is always having fully charged batts. I could, of course run some low carbon footprint/emergency LED lights in the house as well. It'd be great to have a setup that I can take camping to keep the AGM battery charged too. (Camping = truck and small travel trailer) Other ideas?

My biggest question is this: What should I buy such that I keep my options open for future expansion with more panels, etc. I've been looking at this lustfully: http://www.ul-solar.com/product_p/stp125p-n.htm , but I know nothing specifically about solar PV systems. I am fully versed in the basics of electricity, physics, sci/math in general. Just don't know jack about this kind of tech.

Comments & suggestions please!

Thanks,

Art

PS: Also have an AIMS high-efficiency 300 watt pure sine inverter.