I have a '94 full size Blazer. (Same as Tahoe) In my opinion, you can't beat a through the roof installation for the VHF/UHF antenna. I like it better than any lip mounts or mag mounts, because it looks more professional, and the wires are hidden. You can do the drilling, don't worry. DO NOT use a drill bit, use a good quality hole saw or a "rotor broach" sp?. The latter doesn't wobble much and makes the prettiest hole. Be sure to use a center punch to before drilling. This way, your hole will be exactly where you want it. Don't drill through the headliner.
If you use an NMO mount, you can do the entire installation from the top. Just vacuum out the shavings, and lower the headliner just enough to use a coat hanger or antenna whip to fish the wire from the hole over to the molding behind the seatbelt where you can run it down behind the molding on the door post.
As for the HF antenna, I use a hustler on the rear bumper. It tunes up fine. Again, I drilled a hole. Use the drill bit recommended for the antenna installation, then use a 3/4" hole saw to make a slightly larger hole in the plastic covering so the insulator bushing will fit properly against the metal. Because the bumper is horizontal, you don't need a ball. Just be sure your antenna will clear the rear glass and tailgate when they are open.
Email me if you want any digital pictures or anything. ko4fv-at-arrl.net
Good luck es 73,
ko4fv