Choice of mulch and disease prevention

[LMinAL]

Last year I had septoria and bacterial speck something awful. This year I am really trying to prevent these diseases (or greatly delay - leaf issues seem inevitable in the south). So far, I have sprayed Daconil since the day of plant out (twice now). I'll be alternating with copper along the way for bacterial diseases. I have spaced out the tomatoes more, made galvanized metal cages for better support and circulation and trimmed off the lower branches to prevent splashback.

Now the soil has warmed up, it's time to mulch! In the past I have used grass clippings and leaves so they could be turned under in the Fall. Since I had disease problems last year, is it wise to continue this approach? Or am I potentially reintroducing over wintered spores? Better options?

Sorry if this is a silly question. Last year was just miserable and I am trying hard not to repeat any mistakes!