Lots of creeking within 2 hours of Denver, depending on your skill level obviously. The Saint Vrains, Boulder Creek, South Boulder, Clear Creek, NF South Platte (Bailey), Big Thompson, etc. All will be running in June, with maybe the exception of Bailey, since Denver may not be needing water till later in the summer.
As for boats....they break out here if you do alot of creeking....buy what you want, but dont get too attached. Best place to buy boats and/or used gear is probably right here on the buzz classified section.
Colorado Whitewater and open pool sessions are the best place to meet paddlers, other than on here.....One thing I have learned is to find a solid crew and stick with them, cuz sometimes you dont know what you are getting yourself into until its too late.