I know a standard chain tensioner like the surly singleator would not work with a fixed conversion, but would this?

is you have track ends or semi horizontal drops, you wont need a tensioner.

and if you plan to ride fix, you shouldnt use a tensioner

Sorry, I meant converting a bike with vertical drops.

id say try it before buying the tensioner. you could get lucky and it owrks. but honestly, unless the bike has epic sentimental value, get another bike with track ends or horizontal drops and go from there.

You can't use a tensioner with a fixed gear and only need one if you are running an ss with vertical dropouts... a fixed gear with vertical drops needs an eccentric hub or bb to set the chain tension.

try a half link chain