I also had cracking problems w/ the cheaper lexan sheet from home depot, so i went back and got the 3/8 inch sheet and it worked very nice, no more cracks while cutting.
Although the second time around i didnt use a saw but the dremel with a circle sand pad (dont know the technical name), just watch out for the hot plastic hiting u (burns a bit). I would suggest the larger lexan it'* a little more expensive but it did the job very well for me. And i am very satisfied with it.

BTW: Hate to be off topic but do u need the to make a bottom for the box or is it fine w/out it?

This was the method I found worked the best for me. It is neater and has sharper, crisper lines. I did use the dremel some, though the plastic does get very hot and will burn you if it hits you while you cut it.

If you do go with the dremel tool do as a reply said and use the sanding disc, cuts much better and is faster than drilling.


Good luck,

Tim