I'm wondering why you'd want to jump from a 3 rim (105) straight down to a 5 rim (101) and skipping 4 (102 and 103)?
When I bought my DE mouthpiece, Doug got me to send him videos of me playing a couple of notes and then he recommended the set up for me. He was spot on with the rim (he said 102 or 103 would be fine). He recommended the J cup (which was a great setup) but in hindsight the I cup may have suited my taste more.
If you go down the DE route you can ask him to do the same?