An 8" F4.....

I've thought about a scope like this for awhile. Here's a Meade
fork mount with the mirror box for an 8" F4.
The OTA will be just about 28" long.

Note the space between the forks have been increased with spacers.

I've made a dew shield as well (L). The stock "trunions" have been replaced 
with altitude bearings to support the new mirror box.

A Meade Fork or Celestron Fork would work just as well.