I use the one put out by William Laut. There is a different set put out by the Britsh Journal of Photography. I know a few people using the Laut formulas.

What I did to prove the formulas worked well enough was expose two rolls of film under the same conditions. One got commerically processed. The other I did. My enlarger settings didn't change at all between the two.

Now I only mix my own colour developer. I've no personal expierence with the bleach or fixer formulas. But the developer is what goes bad quickly and benefits from home mixing most IMHO.