HD53: no matter what you do, get some more fuel delivery happening than the stock carb w/ stock jetting is going to deliver. The SE CV44 carb may be a good choice once you get the jetting right, if cruise control is a must. A CV carb will accommodate somewhat for altitude changes, whereas the MIC 42 won't nor the S&S. Bet once some fuel happens, the seat of your pants will feel the kick.
If it were me, I'd just take it one step at a time. At this point, even getting the jetting right on your stock carb is going to produce a significant effect. The Dynojet jetting kit with the new needle, main jets w/ needle jet and CV diaphragm spring is a good bet. You'll still need a larger slow jet(maybe 45-46). If I got the CV44, I'd wait and see how it works after getting the jetting right. Then decide if I need the DJ thunderslide. The thunderslide will never be a replacement for correct jetting. It will mostly allow for more rapid acceleration. It has a lighter slide with a more aggressive cut-away. Alot of folks don't like em because it swipes some of the bikes smoothness as well as other issues.
I suppose, I might be looking at the CV44, depending how many more duckets I had left. Might even find a used one or NOS online.
My 02....