Why wouldn't your seat post work? If it's 27.2" it should fit just fine, unless you're concerned about the proper length. The Kinekt does offer some varying length options, if that's your issue. Of course, it's best to go with the shortest seat post that will work for you, for minor weight considerations.
And yes, I am still using the stock tires. I like them okay, except that I have to be extra careful around streetcar tracks now. I might be interested in a wider, more suited to on/off-road tire. These also seem to occasionally grab pebbles and send them rattling up through my front fender. No harm done or anything, but the noise is a little jarring when it happens.