Not necessarily. Your solar controller doesn't care anything about your battery bank, it just sends the proper voltage to whatever batteries you have in order to not cook them. Your solar controller cares about what
panels are attached to it though. That's the most important thing.
In my opinion, which is a KISS (keep it simple....) opinion, PWM vs. MPPT is not incredibly important, but if you're going for AGMs you probably want MPPT. Also, I understand your confusion/hesitation after hanging out on the Transit forum for awhile. It seems those guys like to make things overly complex.
Here's a simple system that will work for 2 batteries (+/-) 200 amp hours.
Blue Sky 30 amp MPPT controller:
Blue Sky Energy Inc. | Solar Boost 3000i
200-300 watts of panels. The sky is the limit here, I'll just link what I've worked with mostly. Cheap and effective. Choose as many as you like, I would go for 2-3 with the above controller.
https://www.amazon.com/Renogy-Watts-...enogy+100+watt
10 gauge solar specific wire from panels to controller with 30 amp fuse/breaker in between.
10 gauge from controller to batteries with 30 amp fuse/breaker in between.
2 AGM or deep cell batteries of your choosing. I like what I'm seeing from Duracell lately value-wise.
From chassis battery to house batteries run 4 gauge cable through an ACR (automatic charging relay) WITH a 80/100 amp breaker. I prefer the Blue Sea stuff. It's top notch and not expensive. I get breakers from Amazon these days.
https://www.amazon.com/Asdomo-12V-24...amp+dc+breaker
I just got a Blue Sea 7610 from this place the other day. Lowest price I could find, very quick shipping:
Blue Sea Systems 7611 Battery Link Automatic Charging Relay
Here's how I did my van between chassis and house batteries:
If you want shore power or an inverter the system gets marginally more complex but not much. What I've shown is a simple chassis battery to house battery system to charge your house while driving, and then solar to house batteries to charge while sitting. All for well under $1k including batteries.
Keep in mind your Transit is not really any different than any other car. There's no magic there. It's got a chassis battery and charging system just like any vehicle before it. Just branch off your chassis battery and add what you like.