Best current single speed adapter?

For vertical dropouts. Been outta the bike world for a bit and was thinking of single speeding up this hardtail that I'm currently building. Good brands.. Best brand? Gears are in the future but I wouldn't mind screwing around with one speed for a while. Also I'm running a 34t narrow wide(didn't even know they existed) chainring what would be a good ratio for pedalling up and going down trails. Like a happy medium for both

Thanks for the help, if this has been asked before I blame the new forum ;)

I used a Blackspire Stinger. I didn't like the dangly spring loaded single speed adapter that just looks like a derailleur.

The issue is that it has limited adjust-ability, so you need to calculate your chain length.

https://docs.google.com/spreadsheets/d/1p0C6JhkooP-3RYgSWXmkvrs9nxWE10_NoPFSzscuA1s/edit?usp=sharing

I'm running a 32-19 and it's definitely hard.