I use an Arai Corsair RX7 RR4 - love it. Expensive, but the weight and venting is worth the money. Visor is easy to change after the first few times. Also use a Shoei RF-1000. Very comfortable, good venting, good choice for mid-range price point. I've used Suomy Spec-1R and Spec-1R Extreme. Good venting, (equal, or a little less than the Arai), light weight (Same as Arai). Shield is a pain in the ass to change. Extreme irridium shield is awesome though, great in day or night. Suomy USA also just died, so that should factor in your decision. My Extreme I ordered came broken, and looked shoddly put together, which is why I ended up with the Arai. For the one-piece, I use an Alpinestars Octane, and like it. Construction is good, and its stretching out nicley. Price is good too for a quality one-piece. You have to go try on a suit before buying anything. The sizing will change from manufacturer to manufacturer.