I almost went with this one. Inatead I Just ordered this one today: Tripp Lite Power Inverter / Charger w/ Auto Transfer Switching, 1250W, 12VDC 120V, 5-15R, 2-Outlets for RVs, Trucks, Fleet Vehicles & Emergency Vehicles (APS1250) https://www.amazon.com/dp/B0007NOUBA/ref=cm_sw_r_cp_apa_jJYoBb5QK3ACY
Like the OP I live in Southern Wisconsin. We've been getting a lot of rain.
I haven't bought it yet, but I'm looking at this Tripp Lite inverter/charger: http://www.amazon.com/Tripp-Lite-APS1250-Inverter-Charger/dp/B0007NOUBA/ref=cm_cr_pr_product_top?ie=UTF8
Yeah, I think isolator might be the better term for what I'm looking for. The part intended there will only connect the car battery when the alternator is running. I haven't tried it yet, but I think the Starter System in my circuit should be able to charge the house batteries from the alternator. It might work for you.
Do I need a DC to DC charger? Should I add that in the Starter System? How does that interact with my bypass switch?
Yeah I'm still on the fence about MPPT vs PWM solar. MPPT looks nice but I like the low cost of PWM and with only 200W I don't know if MPPT is worth it.
I use a CyberPower CP1500PFCLCD PFC and it will only power my modem and router for about 5 hours.
To run as long as you want you could try the following as it will accept any type of lead acid battery though you should probably use a deep cycle battery. You can check out others similar to this by scrolling down to "Compare with similar items". I use something similar to power my cpap machine and it will run it for at least 2 weeks, 8 hours per night with the cpap water tank heater on.