Would it be a good idea to get the "main part" of the Reese bar put on the Tahoe so we could just "pick up" the correct # bar?
What you propose is possible, but buying the hitch piece by piece can be somewhat more expensive than purchasing it as a total system. Depending upon the system that you choose and your tow vehicle, there will either be three or four major components involved.
The first component would be the receiver which for all intents and purposes is permanently mounted to the frame of the tow vehicle - - this is one part that usually is not included in the complete hitch assemblies since it has been included by manufacturers as part of the heavy duty trailer towing packages for a number of years.
The second component (that would be part of the Strait-Line Hitch package) is the adjustable weight distributing ball mount. An important consideration with this is the amount of drop that you will need with your vehicle in order to get the proper hitch height - - if your Tahoe is a K1500 series, a deep drop bar will likely be required - - especially if it has the Z71 package.
The third component (that would be part of the Strait-Line Hitch package) is the Reese Dual Cam Sway Control, weight distritubion bars, and snap-up brackets. The hitch weight of the trailer needs to be closely matched to the rating of the weight distribution bars for the Dual Cam system to be most effective, at least in my experience with both the Overlander and Minuet 6.0 Metre.
The Strait-Line Hitch package carries Reese Part Numbers of - - 66072 (600 pound bars) - - 66073 (800 pound bars) - - 66074 (1200 pound bars). More detailed information about the two main components - - the adjustable weight distributing ball mound and Reese Dual Cam may be found at:
Reese Weight Distributing Adjustable Ball Mount
Reese Dual Cam Sway Control
Also you might need to add a Bargman type 7-pole trailer wiring harness and connector to your Tahoe as well as electronic brake controller for the trailer brakes to complete this portion of the "towing package"
Good luck with your project!