um, why not just get mechanical, they have 2mm activation/deactivation...And you can use the O ring mod ($10) to both dampen, AND reduce the total travel to total of 2.5-3.5mm, not to mention FULL NKRO
if you spend 35$ that works for 20M, the $80-90 for a mechanical that'll do 50 million is well worth it. and equivalent in terms of keystroke to cost.
The cherry mx blue, cm storm is selling for 65$ shipped at NCIX, usa. that + the o-rings either from the group buy, or wasd keyboards. = $75 - $80 total