Welcome to MBc. That is not a very unique problem you have. Several manufacturers, our sponsors, make kits to solve your problem admirably. One is Staton-inc, another is Golden Eagle. Both are reputable and reliable. We also have sponsors equally reputable who make kits that will mount over the rear wheel, and to the rear of the seat. Again, welcome to the MBc.
Find a quality kit to install on the 1997 GT LTS-3 that I have just sitting on my patio.
The bike has been well used and beat over the years - I rode it everyday for about a year, then my son beat the snot out of it and then my wife started cruising the neighborhood with it because she liked the soft ride. When it left me it was all in good working order but now it looks like shift levers etc are cracked and/or broken. But the frame is still solid.
I know I can mount a disk up front and I think I can mount one in the rear. I am thinking step on will be to completely re-build and freshen up the bike, brakes, shifters, maybe even new wheels and tires.
Yes they are, very cool. But when I first started looking at them I had completely forgotten about the full suspension GT out in my shed. I think I would rather motorize that than buy a BMX bike to work on.