If you're up to the frame mods, brake lines, parking brake, adding the additional body mounts, etc. then using the truck frame is a good way to go. It'll be bulletproof for towing/payload that way vs. the 1500 Tahoe.
If you want to be lazy, get the wife a 2500 Suburban. That's basically a bolt-in. My brother and I built my Duraburb with a 2500 Suburban and it was cake. 2 weeks start to finish over Christmas / New Years. You lift the body off, remove the original engine/trans/TC, swap motor mounts on the frame to the diesel ones, move the trans crossmember back ~1", new rear driveshaft, use stock truck front driveshaft, 2" body lift (Suburban frames don't have it built in like the trucks), and some fuel plumbing. Electrical is documented various places, just swap some wires around and use the Suburban fuse block (so the rear AC and all that still works).
For your Tahoe plan, it is much the same, but with more frame work. Electrical will be the same, and just put the whole front clip off the truck onto the Tahoe body (fenders, core support, hood, etc.).
For the ABS and other modules, it is not as hard as it sounds on the GMT800 platform. Every module has the VIN stored, but only 2 modules use it for anti-theft. The BCM VIN is considered the "master" VIN.
- The high-end touch screen radio compares its VIN to the BCM, and won't work if it doesn't match. Just do a theft relearn with a Tech2 and you're good to go.
- The XM radio receiver does the same comparison, but no way to reset it. Easiest is to keep the XM and BCM as a matched set, or you can send the XM box off to get opened up and reset, but it isn't super easy to do.
For the ABS, you want to use the ABS module that matches your axle setup. There are 2 main versions, the 1500 version (what the Tahoe has) which is 4-wheel ABS, and the 2500HD version (what the donor truck has) which is 3-wheel ABS. On the 3-wheel version, the rear axle only has one brake line going to it, and it has no speed sensors. The ABS gets the speed information from the ECU, which reads the driveshaft speed. The 4-wheel ABS module is superior (and has the potential to have Stabilitrak traction control), but it is a lot of wiring to switch to that style. You'd have to add tone rings and sensors for the rear wheels, and add a ton of wiring. I would be inclined to stick with the 2500HD (3-wheel) ABS setup on your swap. The VIN in the ABS doesn't have to match anything, so I wouldn't mess with the programming at all.
Overall, what I like to do on modules is to leave the BCM VIN matched to the Tahoe, then update the VIN in the ECU to match the BCM/chassis as well, but that isn't necessary. The ECU uses a seed/key setup for security that can be learned even with a VIN mismatch. But it is often simpler for smog checks if the ECU VIN matches what is on the door card, and you are almost certainly going to want a tune anyway.
Good luck on your project, a Durahoe sounds like a fun thing!