So far I've used a BOSS GT-6 multifx pedal that gives you a nice clean sound as well as badass distortion. Might change this to some rack equipment in the future, as it's not the most convenient one to program and carry around.
With my violins I have stuck to Yamahas. There's a nice price/quality relationship and if problems arise I can get a similar one pretty easily. Originally I used EV-204 but I broke one of its piezo mics earlier this year, and while the violin's being repaired I'm using SV-120 model.