First, welcome to the Forums, I think with a little looking you can find the answer here to almost any trailer question you might have.
I would first ask why Lexan ? Yes I know the benefits, but you can get just about any size glass cut for about the same price if not cheaper and remain consistant with the rest of your windows. I recently built a roof vent cover from Lexan, and that stuff is not cheap. The Lexan that I used was 1/4in and I think the glass was about 3/16th. Just a thought.
Regardless of which way you go, you could treat them the same with regards to the installation. VTS has most of the stuff you will need. I have the HEHR Windows and used the Glazing tape and and Hallmark glazing strip and it worked well.
Best of Luck...