I have an 05' PSD with 155k. It would be fun to mod this for more power. I have casually looked at a Banks powerpack. I guess I have some questions about power and reliability.

1) what are everyone's recommended mods for power ? Anybody used Banks ?
2) At 155k would is there anything reliability-wise that I should definitely do or should I just have fun and do head studs, etc if/when I have head gasket issues or other major problems ?