I plan on doing that today.
I also need a comfortable seat that looks good (anyone know of any?), I'm considering getting one of these as well... (U.S.E. Carbon Sumo XCR Seat Post)
Stay away from suspension seat posts. If you want suspension, get it on the saddle:
Since you just got the bike, hold off on getting a new saddle for a bit. Your butt and the saddle need time to get acquainted. Lycra shorts, either roadie or mtb. style, will prevent chafing and be more comfortable in hot weather. There are several shorts available in hipster style, too that look really nice that you can wear wherever.
It's cheaper and easier to swap cogs than chainrings. If you are running 42-17, get a 16T or 15T cog. That'll increase your speed plenty.