Sounds like you already heading in the right direction.
The all chrome Tahoe style grille shells looks good on there. You could replace the billet with a tighter billet insert (basically has more bars in there to fill it in better), and do a billet bowtie. The paint matched bumper top pad along with a new bumper should complete the look really well. Throw some 2003 and up Silverado tail lights in the back. Color matched door handles, tail gate handle and bezel would look good as well. I really like the stance of the truck as it is, I'd go with some Tahoe LTZ 20's....
2002 Silverado 2500HD LB7 CCSB LT
EFI Live by Rob at ATP, Edge CTS Insight DSP 5 control, S&B CAI, PPE boost valve, Pro Fab AIH, AirDog II 165, PPE WIF sensor delete plug, 5" stainless exhaust, Cognito braces & HD tie rods, H2's 315/70 R17 BFG's
2004 Tahoe LT
2006 Silverado Z71 LS
1971 Chevy C10