Hi,
You are over thinking this.
The solar system should be wired directly to the "house" battery bank. It will have a charge controller on it. I would consider adding a trik-l-start or amp-l-start unit so the solar will maintain the "starter" batteries too.
Here is a simple flow chart.
Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT. What ever type of controller is chosen, make sure it has adjustable set points and a temperature probe that is on the battery.
One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!
Solar Spread Sheet N8GSFor a nice explanation of solar, try this link:
Golden rules of solarIf you plan on full time off the grid, then maximize the solar farm size and lean towards higher voltage panels with an MPPT controller.
