Ok so I found a local guy that's got a good rep for building trannys and I'm wanting to know what all I need to add or change in the tranny for it to hold up to my mad driving style, or what are the weak spots in the tranny...like the 3-4 clutches. It's a 4l60e out of a 98 Camaro z28 I'm running the stock horsepower and never track it . Apologies if there's already been a thread like this.

 

Not to be an a-hole, but there are 100+ threads like this. (That is why no one has yet replied.)
For your application, I would:
* Ask your builder to get a 2003 4L65E rebuild kit as this will include a high-energy 7-friction 3-4 clutch set. I got one from the huge Transtar distributor and it included the Raybestos GPZ105 frictions, which are their latest ones based on their Z-Pak.
* Add either "The Beast" or the newer (and $20 more) Sonnax Smartshell.
* Get a 13-vane pump kit (about $40)
* Make sure the builder replaces the separator plate. ($25)
* Make sure the builder replaces the accumulator pistons with aluminum ones. ($10)
Optionally consider having the Transgo HD2 shiftkit installed at the "lightest" settings;
the resulting higher line pressure will extend the life of the clutches.