My wife and I chose the prefinished because the unfinished requires sanding, finishing, sanding, finishing, sanding, finishing, etc. Which would have meant that we would have to be out of the house for quite some time, there would have been sanding dust everywhere, etc. Also the need for finishing made the installation labor cost a lot more, which increased the price of unfinished floor. With the finished we had professional intallers put in five rooms in about two days and we could actually sleep in it each night since there were no finishing fumes. the only dust was from a saw in the area where they cut the floor planks to fit when needed. We chose Hardco (I think that's the name) floor with the grooves because that also allows for expansion of the floor as moisture levels change through the seasons. As far as dirt in the grooves, we just use a vacuum with a good soft brush on it and it looks graeat. We also got one of those power broomvac things for "accidents."
In terms of "kits" make sure they are not the "laminate flooring," which looks like but is NOT wood, but rather a picture of wood on the kind of stuff used on some counter tops. It is usually laminated on particle board. There is also the laminated stuff which has a thin layer of the wood over something like plywood or particle board.
I have never seen wood floor being installed with glue. It is usually nailed down on the lip side with special pneumatic nailers.
I have seen laminated glued to the subfloor, which is very tough to remove when replacing (is what they had to do to my entry way to remove the junk that was there to put in the wood floor).