From memory the only member on here with bags or atleast installing them in a 1200 ute is DiscoStu, I dont think he frequents here much, from memory he moved to QLD and his ute was put on hold. Does his ute lay out? who knows?

Since the ute is momocronstructed ( doesnt have seperate chassis) you are best to go speak to a shop that does installs and has experience with vans etc.
Without measuring the ute and knowing wheel diameters, I dont think a C-notch would be enough to get it to lay sill. All a C - notch is, is a piece of pipe cut in half lengthwise and then sectioned into the rail above where the axle tube will be positioned at lowered height. Since the rails are only about 1 and a half inches heightwise that will be the maximum extra drop a C- notch will give, even then you will have to add a box section above the C - notch to help retain the structural strength on the rear of the ute..

I am sure you could look at many magazines with airbags and work out a way to notch the rear of your ute and still provide adequate strength to the body so as to allow the rear of the ute sills on the ground.
( If you cant I would give up now)

As to the front - unless you gonna run tiny rims, there will be a need for plenty of re - engineering of the front suspension to get the ute to lay sill evenly front to back.
From memory the crossmember in a 1200 is way lower than the sills, means even more work.

If your keen, I dont see why you cant possibly get what you want. But I doubt you will be able to get much help from anyones experiences on this website.