Are there any performance options for this trans that can stand up to some abuse?

The torque converters at zzp/intense will work.

LSDs and gear swaps of 3.33 and 3.73 are offered by
http://www.engineered.net/
A LSD for my car is 575.00 and if i add on a 3.33 gear conversion it'* another 150.00
It turns out that they won't sell the gear conversion unless you buy the LSD.

And i know that i've read somewhere that the 4t65 clutches fit the 4t60 with the exception of modifying one to fit, in which case you can get Raybestos clutches from here:
http://www.transmissioncenter.net/alto_2.htm

I found this site not too long ago and it'* the first site i've seen to offer a modified valve body.
http://www.importperformancetrans.com/gmautofwd.shtml

Other than that there is a trans line pressure adjuster that B&M puts out and it firms up shifts . I've read on other boards that it has no 1/4 mile gain though.

Not to be a gerk or say your wrong or anything, but can anyone else verify that the parts are innerchangeable between the 2 transmissions?

Some hard parts that ZZP sells for the 4t65 will fit the 4t60. I have seen 2 built ZZP 4t60 transmission in person.