There's no denying that a proper retrofit is the way to go. However, speaking from experience, it IS possible to do a "kit" that produces usable lighting without putting other drivers at risk. Most cheap kits are just that. Cheap. The beam pattern is terrible and the look for oncoming traffic is not at all safe. 50 watt kits should not be installed in ANYTHING.
There is a reason these kits are not DOT approved. The stock headlights probably should not earn a DOT rating either. The beam pattern on stock lights is a train wreck. It's only the fact that they are weak halogens that doesn't cause problems as they are produced. The stock headlights in these trucks are particularly bad candidates for a PNP kit. Not all headlights are. I did a PNP kit my old Audi A6 that had halogen projectors that was awesome.
My first attempt at a PNP kit for the Tahoe was a disaster. Twice as bad as stock, and no brighter. What I've come to realize is that not all PNP bulbs are created equal. After three attemps and not being satisfied with the results, I started looking closely at the bulbs. It takes only the slightest difference in where the arc is placed as opposed to the halogen filament to make a PNP kit all but unusable. I finally found a set of bulbs that made a respectable beam pattern (5000K), and these seem no more glaring coming towards me than most factory HID's (better than many).
The downside is, accounting for my time, I've bought a true conversion 1.5X already (at least). Back when the truck was brand new and I started this, there really wasn't a good option for a conversion. What I have now is the best you could hope for out of a PNP setup and it, of course, looks like fido's ass compared to say, my E55.
I have not found another set of bulbs that does what I need, not even from the same supplier. The quality control is just not good enough to make going down this path worth the trouble. Now that we have sources like Black Flame that can just give you a replacement set of lights ready to go for about a grand, it doesn't make sense, but a PNP setup could possibly work. If anything dies, I won't waste the time and effort to make it happen again, a real retrofit will be next.