Charge controller and battery bank size recommendations for 860w of PV on Sprinter

[SupraLance]

Regarding that laptop usage, you should look around for a car charger for it and eliminate the inverter loss altogether when you are using the laptop.
Regarding blue solar/smart solar, only difference between the models is the built in bluetooth vs needing a separate dongle to interface with bluetooth.
Regarding charging a 24v battery with a 12v alternator, there are converters that can step up the 12v output of the alternator to 24v to charge those batteries.

[Withalligators]

Cool, so, since I have 2 series in parallel, should I have a 30 amp breaker coming in to the controller (after they have been T'ed together)? How about from controller to they battery?

I'm second guessing my choice of the 150/85 mc4. It has three pairs of mc4 connectors. Seems ideal for when i have 3 panels, but, until then, can i run both series in parallel into a single pair of ports?

I've looked for a 12v adapter for it. Doesn't exist, unfortunately.

[Sunking]

Cool, so, since I have 2 series in parallel, should I have a 30 amp breaker coming in to the controller (after they have been T'ed together)? How about from controller to they battery?

Again there is NO REQUIREMENT to install fuses or breakers between the Panels and Controller. You are permitted to add them if you want, but it you are going to use a 30 amp breaker means the minimum size wire you must use is 10 AWG. You cannot apply a 30 amp breaker by electrical codes to smaller wire than 10 AWG It must be 10 AWG or larger.

From the OUTPUT of the CONTROLLER to the BATTERIES, and from the BATTERIES to the LOADS you are REQUIRED TO USE OCPD (over current protection devices). Try looking at the drawings I provided you as it answers your question in great detail.

I'm second guessing my choice of the 150/85 mc4. It has three pairs of mc4 connectors. Seems ideal for when i have 3 panels, but, until then, can i run both series in parallel into a single pair of ports?

You should be because you have not read the manual now have you? The 3 inputs ARE NOT FOR 3 PANELS, they are for 3 STRINGS of panels. Its a clever design idea so you are not forced to use combiners and fuses which cost big dollars. If you had read the manual you would have that question answered in detail;

MC4 models: Several splitter pairs will be needed to parallel the strings of solar panels. Do not exceed the maximum current rating of 25A per connector pair.

What that is telling you is the Controller can accept up to 3 String of Panels, and thou shall not exceed 25 amp input current.

I suggest you try reading the manual.