Which 75mm?

I am considering the purchase of a 75mm for my Leicas (a pair of chrome M6s and a buck ugly black M4-P) and would like some input. I currently own a 28mm Summicron ASPH (6-bit), a 35mm Summicron, a 50mm Summicron, a 50mm Summilux ASPH (6-bit) and a 90mm Summicron ASPH (6-bit). The 90 is, for the most part, my portrait lens. Often, however, I find the length less than ideal. Similar to my Nikons, where I often favor the 85 F1.4 over the 105 F1.8 as my lens of choice for shooting portraits, I also have often found the 90mm a little "too tight" for some of my shots. Hence the interest in acquiring a 75mm. My question is: Which one? Leica has, at various times, offered 75mm Summicrons and Summiluxes; currently they also offer a Summarit. An M9 or M9P may be in the future - if I can ever get over my E100G/Tri-X fixations - so the 6-bit coding is not really a critical issue. Thoughts?

though i havent used the 75mm, as i understand it the difference between the summicron and summilux is a stop and a whole lot of weight. the summilux opens to f/1.4 where the summicron only to f/2, but the summilux is older and gigantic.

imho, i would go for the older lens, the summilux. although it is a beast, i like the additional stop. shallower depth of field and so on. i dont mind a large chunk of glass, i use tripods.