I have a 62cm Titan that's made with SLX that rides like a dream. I only weigh 160 lbs though, so that may help it.
I'm going to assume that since yours is made with SLX, it's a pretty racy frame. Odds are you won't even be able to fit 27" wheels on that- not with tires anyway! As for new components, they should mostly work just fine. The only issue is the spacing on the rear wheel, which can be changed, search around for "cold setting". Also presumably the head tube is sized for a 1" steerer, so take that into consideration when shopping for forks, as most produced now are 1 1/8".