I don't have slides, can't help there.
Vent covers are great, I don't know why they're not standard equipment. I installed mine, bought from Amazon two for $20 total shipped. Took maybe 30 minutes to install using self drilling screws instead of the junk nuts and bolts they came with. Now I can leave the vents open and not worry about rain, even when driving.
Surge protector I bought an expensive inline unit due to pressure from this forum, surge protector have a strong fan club on this forum. It's not compatible with the way my inverter tests the shore power. It's buried, unused in storage for three years now.
2013 KZ Sportsmen Classic 200, 20 ft TT
2020 RAM 1500, 5.7 4x4, 8 speed