Ideally you'll want to charge your battery bank while you're driving, from you high output alternator. If you're not driving frequently you'll need another way to charge the battery bank. So solar, shore power or a stationary bicycle hooked up to a generator.
For charging your battery bank a lot of people are using a charge wizard. Not familiar with it, pretty sure it runs off of 110v.
If you're on shore power you'll have to decide if you're going to have two electrical systems, 12v and 110v, or power just your 12v system with the shore power. Lighting is probably just short of adequate on 12v.
A Converter (I think) is to change 110 to 12v to charge your battery bank, and the inverter that changes 12v to 110, but I get them backwards sometimes.
You'll find lots of tanks for sale on Craigslist, including new ones. There might be tanks listed in the phone book but I haven't found them.