My first advice is to ALWAYS get "direct acting" jacks, and it appears every BigFoot system is direct. HWH is another company and good to my knowledge, but some of theirs are "kick down" and I consider that a major weakness. Spent a lot of time looking at BF's webpages. Their most basic sytem is $2200 (plus installation of course!) but it's a Single Pump (connected to Jacks with Hoses) system not their famous Four-Jack (one Pump per Jack) system that's about $1000 more. And UP, depending on how much electronics you want.
I tried to research DIY Installation. It didn't look too bad, but their video and pix showed chassis with no Coach, Tanks, etc. etc. aboard.
What concerns me is the Welding. Jacks bolt to Brackets but Brackets Weld to Chassis. Since I don't weld I'd need somebody to do that part. I think that would be a Tech Issues item. From my limited exposure to welding, I think both terminals of both Chassis and House batteries should be disconnected, and the welder Ground should be attached, maybe even bolted, to the Chassis four times, close to each bracket weld. Again I'd check, but perhaps Wire Welding could be an option to traditional Arc.
BF's basic systems operate the Jacks in Pairs. The idea is to not rack the chassis lifting one corner or opposite corners. I don't see that as a drawback because the jacks are direct acting. We have HWH Kick-Down, and one of their two disadvantages is they don't always kick to vertical before extending. I often have to pull on one to get it straight. The other disadvantage is the pivot mechanism can wobble a little so kick down doesn't provide the stability of direct acting.
BF shows Required mounting locations for Front Jacks and Options for Rear Jacks. My advice would be to get as much separation as you can. Rears in the Rearward of the two positions they offer, and on the Outside of the Chassis if you can. Jacks on a short coach tend to lift the whole coach as you level. By the time you achieve level, the coach may be higher than it would need to be if the load lifted from closer to sides and ends. We had a 24-ft Class C with 158" wheelbase. It wasn't unusual to have a front wheel off the ground before we got level. That was even if the campsite wasn't grossly cockeyed, and with an older HWH system that let us work one jack at a time.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB