I had a pair of EV covers that are made for the SX300, and I tried them on the SXa100 just for kicks. They STREEEETCH over the body ok, but the heatsink fins will definatly cut them with any kind of friction. I wouldn't recommend these covers. As a great alternative - The covers that Mackie makes for the SRM450's work great - they are a little big, but the excess fols in nicely when it has too. Greta handles, pocket, and a flip up lid to access the side hande on the EV - works PERFECT.
Every instrument, every voice, every sound in nature ... these are are all my private tutors ... 24/7 for free, and all I have to do is listen.