The fastest way to MCO is to become an instructor. After that it's a crap shoot, but Mco is arguably the most senior base tied or second only to LGB.

Behind becoming an instructor the 190 is likely the fastest way in. Conservatively I'd plan a year or three. Mco on the 320 probably 2-4 years unless we decide to finally grow the base. But they've been gonna grow Mco for at least 9 years. We've literally gone years with 0 (zero) movement in MCO. Ymmv. Believe me there's a lot of us hoping you get Mco fast...