On the bike, HED Trispoke front, or a Zipp 808. (The front wheel is more important than the back). Also,if you haven't done it, have you considered getting fitted by someone who works with Triathletes. Sometimes minor position adjustments can lead to more power with little or no cost to aerodynamics. There's a guy here who does fittings on a computrainer with a power meter, and also measures frontal surface to the wind. He's had clients improve more than a mph, often by raising , rather than lowering, their position.