Even the 12" rotor upgrade and some hawk pads would be nice. The LS1 calipers don't offer that much more braking force compared to the 12" rotor w/ stock caliper.

Suspension wise, new front LCAs, some non-stock trailing arms, and some nice shocks. Bilsteins if you have the money, if not, KYB Excel-G/GR2. Avoid AGX, they're very hit or miss.