Homemade Solar Generator

The other day I was in Costco, and they were selling a "Yeti solar generator" by Goal Zero.  It's basically a battery with a built in charger inverter into which you can plug solar panels (separate purchase) to charge it when the grid is down.  They say it's 1250 ah, but don't say over how long.  My impression is that it's a self contained, easy to use system for people that don't want to take the time to figure out how electricity works.  Kind of like the iMac of renewable energy.  But like the iMac, it's pricey - around $1,200, and seems very limited.

I decided I wanted to build my own, and "hobby" my way into a backup energy system.  I don't want to debate batteries, I'm just going to go with 2 Trojan 105's for now because of their ubiquity an the pages and pages of info about them.  What I'm unsure about is the charger/controller.

Most of the info that I find is too simplistic and is of no use or too technical and I can't understand it (and is of no use).  What I want is a charger/inverter that I can plug into the wall (I have currently have plain old grid service) to keep it charged, but can add a few solar panels to as it grows (and I learn the language), and a small generator.  Basically an RV system, without the RV.  Do I need a charge controller?  Is there a difference between a controller and a charger inverter, or is the terms interchangeable?  And does MPPT come into play with this small system I'm looking at?  I'm thinking I want to stay at 12 volts, and around a 2000 watt inverter.

Please discuss...