If you easily want to find spare parts for your engine, just in case - I'd say go with OS 46AX -
I got mine from my friend with ~5 gallons thru it, i put at least 5 more, and now its just sitting on my plane as decoration in my room - but i know if i fuel it up and flip it, its gona start right away..

extremely easy to start & tune.

for TT, i guess its just as reliable, but still i'd go with OS for 2 strokes.