any good plastic replacements in the bay area, CA?

after reading all the different ways folks have changed their back plastic,
I think I'm leaning towards cutting out the plastic, and glueing a new one
on. My question is what type of plastic is best to use that you can get from
hardware stores.

I'm in the san jose, california area - is there anything I should look for
from the local hardware stores? are there any plastics that resist yellowing
better than others? how about tinting the new plastic - is that
possible/helpful???

also, has anyone been able to take out the palstic border that is glued to
the top? I was planning to just hot-gluegun the new plastic ontop of the
original border once the inside was cut out but I'd rather not have the old
yellowed border under the new plastic, and I think the new plastic would
adhere better tot he top directly then to the old plastic leftovers...

thanks,
thomas