The purpose of capacitors in a Tesla coil is to create a resonant circuit with the primary coil. The current which they will be seeing during operation is about as pure a sine wave as you'll get
Hopefully they will perform well, just be aware that MMCs often blow a cap here and there. That's one of the main reasons they were invented - to make it easy to change just one or two (relatively) cheap capacitors instead of having to replace a single, giant, expensive capacitor. 942Cs are fairly rugged, but don't be surprised if you lose a few.
P.S. Oh, and please, call me Matt!