I don't think you need a ton of time. Fly High makes fittings that would link you up directly to your factory lines.
I redid my 210, everything was fairly simple and it would have taken me less than a day had I not rewired the entire ballast system as I had one fill switch and wanted control over the back ballast for balance.
If you have separate switches for each tank, it's a walk in the park. Call em and I bet they already know what you need.
I tried the piggyback thing, it works but big sacks are the way to go. You also get all that room back for trailering.
my 02 cents