Keith,
I have a MPP Mark VI and I definitely cannot close it with my 210 Symmar which is the closest that I have to your 180mm Symmar. Of course the 210 Repro Claron allows me to fold the camera easily. The longer plasmats might not be a good idea if you want to carry it with the lens mounted.
I envy you, the Mark VIII has the revolving Graflok back. That is a handy feature. These are great cameras, though a bit heavy to tote around. I had Camera Bellows make me a new set of bright red bellows for mine which really make it look sharp.
I doubt it is the best, but I have a Toyo loupe that has a longer barrel on it that lets me focus with some of my older speed graphics with the non detachable focusing panels.
And though you probably already know this,
http://www.mppusers.freeuk.com/ is one of the better resources for information on these cameras.
Good Luck!
Harold