You know I am going to suggest you look at something. A 6/8 is way more solid than a 5/8 in standard steel let alone SS. SS will be a lot stiffer. I had trouble with a 5/8 because of my beard and went to a 6/8 and it was all the difference in the world, it is very smooth. Just a thought. You know you will probably end up with both anyway and a 6/8 is the most used size of any razor, period.
Take Care,
Richard