I have a 5+ year old Dahon Mu P8 that needs a new derailleur cable. Instead of getting a new cable, I am looking to convert it to single speed since I've been stuck in the same gear since the cable broke anyways. And even when the cable was working, I stayed in the same gear 99% of the time.

From what I can tell, I can just leave the cog I want to use on the hub and replace the rest with spacers. I then would need to replace the rear derailleur with a chain tensioner. Does anyone currently have one on their Dahon that they recommend? I found a bunch online such as the Summit Godspeed, Surly Singleton, Rollen Rollenlager, and Soulcraft Convert. From what I've read the cheaper ones use spring and tend to wear out over time and the more expensive ones are a solid piece and are more reliable.