Suspension Swap 1990 to 1999 & Later

I am new to this site, so thank you for your patronage in advance. With that said, I have picked up a 1990 LX 5.0 5spd Hatchback. This is Dad's next project/toy. Looking to convert to an updated suspension, and wondering if 1999 to 2003 running gear will bolt-up? This will be a slow moving project, so I've got the time to R/R whatever is required. Possibly a donor 2000 GT?

Thanks again

Part II Suspension/Brake Swap

Is it possible to just change the axles, backing plates, disc brake assy. from the 1999+ axle housing to the 1990 axle housing. And, can the same be done with the front spindles from a 1999+ to the 1990?

Suspension & Brake Swap Con't

Back to the swap scenario. Where I'm intending to go, with this Mustang, is "Road Course" set-up. I'm a NASA, SCCA, SPEED GT, Long Beach GP, kinda junkie. That said, I'm also watching the "Green Backs", during this economy, if you know what I mean. So, I'd like to take advantage of the unfortunate souls who's cars now reside at the local Pick-A-Part wrecking yard. My curiosity wonders if I can just unbolt a bunch of stuff during 50% Off days, and transfer as much as possible. I'm talkin' both L & R front control arms, spindle assy., all of the front running gear. Also, the complete rear axle assy, drive shaft, upper & lower control arms, E-brake, all of it. I had a 2000 Mustang GT, (my EX-WIFE rolled & totaled it after the divorce) and there were some improvements in design over the previous years. The front spindle assy and brakes at all four corners were some of the areas I was interested in as well as the 5 lug benefit. I understand the general geometry is similar and, if possible, I'd like to add as much of that to my Fox Body as possible. I will, however, stay loyal to the push-rod 5.0 configuration. If the general consensus is to stick with 94-98 running gear, then that's the direction I'll head. The future would have a Watts-Link, Tubular control arms, coil-over rear suspension with Cobra Brakes, and Maximum Motorsports Full K-Member, coil-over tubular a-arm set-up. However, that's "LONG RANGE" at this time. Thanks for the imput.