If you post up a thread, or just for reference, since there aren't a bunch of 3100/3400 guys that post over here...
For Performance stuff you can check out...
Milzy Motorsports - American Muscle, Reborn
ZZPerformance
eBay | Electronics, Cars, Clothing, Collectibles and More Online Shopping - For Cheap 3100/3400 Pacesetter Headers
For more mods and info, feel free to check out...60DegreeV6.com - Site News
Hope this helps, if I have left anyone or something out, please feel free to add it on, as I'm going to sticky this and hopefully anyone that visits this section can get the answer they are looking for.
Thanks,
Nick