Snaz75.com for a huge selection. Several versions of their "Dolly" shoe can be modified quite easily.
Cutting the toe open (if needed)
Neither leather nor pleather will fray. Carefully cut out the toe area with a blade. Straps can also be moved if needed, but it might be better to have a shoe repair shop stitch that down for you. Since women's feet are typically narrower than men's, you may also need to install an elastic gusset on the vamp like Tim's.
The sole should be black; paint if necessary or your finished shoe will look weird. Paint the outside heel area white (use tape to protect the shoe upper, sole and the heel tip). Spray paint is easiest. The lining of the shoe is silver.
I prefer Super-77 spray glue by 3m, but if you're going to spray you need to conceal the other areas really well with tape, etc. I also recommend covering your work area with a paper grocery bag to catch the excess glitter. When you sprinkle the glitter on the glued area, press the glitter in firmly. Tap the shoe on the table/counter to get the excess off. I did the black areas first, then very carefully did the white heels. The straps do not have glitter on them.
Cover the shoes with multiple thin layers of a clear coat. This will minimize any further glitter shedding. The key word here is thin. If you spray too many layers too quickly, or too thickly, it will turn yellow and dull and pretty much ruin everything you've done.
Use e6000 or any jewel-tack glue to apply the clear rhinestones to the heel.
If you're lucky to find one on other shoes you've got it made. I haven't even had much luck on eBay or Etsy. You can at least paint the existing buckles silver (if they aren't already) and glue some tiny rhinestones on the top bar until something better comes along.
I've never experimented with heel covers (to consolidate the shoe change between Sweet T and the Lab Scene), but I've heard of some pretty clever solutions that seem to work well - and please feel free to add any tips in the comment section!