First question....
My first question would be "Why?" The SP101 is already built like a tank, so additional cylinder strength is not neccessary. In addition, an unfluted cylinder will add at least 2-3 more ounces to the already heavy SP-101.
If want an unfluted cylinder for no other reason than aesthetics then by all means do whatever flys your flag. Just be aware that you will be comprimising the relative carryability of your gun.
Brad