I have a Gary Fisher Nirvana hybrid that came with a horrible suspension fork. I just didn't know any better at the time. It didn't have a lockout and weighed about 6 1/2 lbs.. I'm surprised that RockShox even put their name on it.
Once you have the proper measurement needed (see Headwind 15 above), the Surley website has a variety of quality rigid forks to choose from. If you're having a LBS doing the install, let them look at your bike and the web site and they can tell you which forks are your best (or only) options.
For me, going rigid made it feel like a brand new and much better bike.