I think that the 3425 is the "purest" of all. The 3440 has a heavy bezel that gives it a contemporary look and interestingly shaped lugs. I own both but do not have pictures. I would certainly suggest that you look at those two before making a decision.
Also, it's important to see the watches in person before you buy them. Some of them seem to be proportioned so that you get funny reflections around the edges of the crystal.