I have a full filter on my 12" lx200, I find it fine. i did use a off axis filter for the transit of venus, and there was a level difference in the brightness, but not much. Just get a full filter and be done with it
. as to what it is made out of that is up to you. each type has it pros and cons. dearest is not neccessarily the best, and the cheapest can be exactly that. Strike a happy medium!