I'm interested in 3 Leica lenses on a Leica Ltm:
-50mm f3.5 Elmar
-35mm f3.5 Summaron
-50mm f2.0 Summitar

However, I am unsure on how to approach the filter/hood situation. I would like to use modern filters and a hood (preferably one that is low-profile). Viewfinder blockage may or may not be important because I might use an external viewfinder (definitely for 35mm but maybe not for the 50mm).

A36 lenses:
I see that i can use a SOOGZ and those are supposedly not too expensive.
For the hood:
-Will summicron hoods block the viewfinder? I believe I will be able to take 'cron hoods with the correct adapter.
-Alternatively, would this hood work? http://www.heavystar.com/servlet/the...rd-39mm/Detail for something that is lower profile.
-Will I be able to change the aperture settings? I read that this is an issue with the Elmar but I am unsure on the Summaron. I'd probably shoot aperture-priority so this wouldn't be that big of a deal (I do not think).

I see that the SNHOO is expensive but SK Grimes and DAG can make replicas; else, there is heavystar. Another alternative is to make my own filters from old Summitar filters..
For the hood:
-If I go with the SNHOO (or replica), then can I use the barn door hood? I read that it really needs this silly-looking hood.
-Does the barn door hood stay intact as well as the other Leica hoods? I have the hoods for the Summaron/Summicron for my M3 and they stay put. I believe the barn door hood folds so I'm not sure how "rigid" it is.
-If I do not want to deal with the hood then do the heavystar wide hood work? (The same one listed above).