nice rig and mods, that thing is clean! Always digged the Crusiers, different than Jeeps. You gonna have it trail ready soon?
I've gone through the same issues as you with the kids, after your youngest is 2+ yrs old (or sooner) you won't need the space behind the back seat so don't be affraid to stick the fuel cell back there now. My youngest just turned 2.5 and I'm looking to ditch my fuel cell under neath in favor of one behind my back seat, I plan to redo the floor board to follow the back seat/top of fender and still have the fuel cell out of the cab area technically.
Have some pouches sewn on the back of you seats to hold Camelback bladders, especially for the kids so you're not loosing the drinks. Bringing the kids up wheeling is great, mine get upset if I don't take them with me.
now, where's the pics of the rear shock setup?