Unless you happen to be in the USA on other business already... I'm there for geek-related business in January and plan on squeezing an MEP in whilst I'm there - will save me a fortune!
Just remember that getting a class rating (like the MEP is) requires TSA clearance and an M-1 visa, plus some other minor bureaucratic stuff.
Differences training like a tailwheel endorsement, to the best of my knowledge do not require TSA or M-1, as long as what you do stays within the SEP(A) class.
https://www.flightschoolcandidates.gov/ - Scroll down to where the background becomes grey.