The answer's a great big NO. These things you're interested in are not headlamps, they are headlamp-shaped trinkets. They are not effective, not safe, and not legal. Don't buy them. It's not a question of losing this or that percentage of light, it's a matter of the wrong amounts of light being sent to the wrong places. Too much glare, not enough seeing, and the signal lights don't work safely, either.
Even the aftermarket lights that look just like the originals are junk. By a large mile, the best lights you can get for that vehicle are the genuine GM items, that is
this one and
this one. If you also need the lower light units (turn signal/daytime running light/side marker), the same applies; that's
this one and
this one.
Bulbs: use
these for the low beams,
these (with their plastic base tab modified as per
this diagram) in the high beams. If you want to spruce up the vehicle a bit, you can put
these in the daytime running lights.
These would be the choice for the front turn signals, and
these for the side marker lights -- nice and bright.
Very, very important: after installing the new lamps, have them aimed
correctly with an optical headlight aiming machine, as described on
this page.