Here’s a great resource for converting to a single chainring. There may be more to it than you realized…
[url:32yq5ks4]http://www.bikeradar.com/mtb/gear/article/trail-tech-how-to-convert-to-a-1x-drivetrain-37451/[/url:32yq5ks4]
Best bang for your buck would be the chainguide option they mentioned, because you could keep your current set up – just remove the small and large chainrings. But as they say, special front chain rings AND a rear dearilleur with a clutch is the best bet. (But high $$.) Good luck on your project! Should be fun.