That Go power kit has a lot of expensive stuff in it, which is fine if you need it all but if you don't and can get the parts you do need elsewhere for less, then you have a choice.
The starting point is how big of a battery bank do you intend? You need a big bank to run a 3000w inverter loaded up. What will you run with a 3000w PSW inverter you can't run with a 2000w one?
How much of a charger will you need for recharging the size of bank you need to run that 3000w inverter? The kit has a PowerMax 75 amper (PF corrected so it runs on a 15a circuit---do you need a second converter?) Can your generator supply the input 120v to run the size of charger you need?
Maybe you want a decent inverter/charger instead and then just get some solar.
Anyway it is all about having enough battery to go with that battery-hungry kit. If you are restricted to a smaller battery bank on the tongue, then you can't get full use from that expensive big kit.
400 plus watts of array might justify going to 24v panels and MPPT-depends on what is on sale, etc.
Wiring it all up is simple enough. You use a buss for the positives that go to the battery by one fat wire from the buss and all your negatives go to another buss. That neg buss can be the shunt for the Trimetric monitor, where all go to the outer end and the inner end goes to the battery neg with another single fat wire.
1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
Photo in Profile
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
See Profile for Electronic set-ups for 1. and 2.