don't know anything about the lenses that 'hide the bezels'. I think you are mistaken in that you can run Left 4 Dead in 3d using cheap 3d glasses (not NVidia 3d glasses which require a 120Hz monitor). Have you got a link?
The lenses he's referring to are fresnel lenses, I use them myself. If you have lcd monitors with very thin bezels it might not be worth the effort, but they do create a seamless surround effect. The effect is far better than it appears from youtube videos etc. Not great for reading/surfing through though.
As to mounting them you have to figure out a way to build a frame that will hold them a few inches from the screens and line the edges up. Like this:
http://home.comcast.net/~seekeating/r/th2go/
I suggest the F550 from 3dlens.com where I got mine. This one is the best available for large [ 19" and larger ] screen monitors. I use with 21" screens. The thing to look for is a large lens with a high number of 'grooves per inch'. Higher = better quality image.
I would suggest buying the th2go rather than messing about with softth. Th2go is far easier and a better solution. Although expensive, it is worth it for the surround experience.
Left for Dead in 3d, with cheap glasses!:
http://gamerslastwill.com/2009/02/02/3d-left-4-dead-for-free-oh-yeah-heres-how/