Personally if you want to run discs I’d go with some Hope C2 and appropriate Hope hubs from 98/99. Easy to find and service and will work as well as can be expected.
Twin front disc set ups are rare. Simply because they didn’t sell many back in the 90s so even less are left now. The money that you would need to part with for the front set up would be more than a LTS2000 is worth (or will ever be worth) so by all meals do it if that’s your true desire
I’d also add that these later LTS frames were prone to cracks on the pinch bolt of the upper pivot. Had many and most cracked.
In terms of investment then I’d agree that some retro bikes will out perform bank rates but unfortunately not a LTS2000. Think of it as a cavalier GLS rather than a SRI130 in terms of desire.
Build it to ride and likely if you catch the bug you’ll be wanting a LTS team or 1 soon enough followed by many many others
Decals can be had from retro decals.
If you start welding disc tabs then any value is gone for a collector. Better to source a rear end.