Hey guys so Ive been upgrading my GT SRS 3 and now my drivetrain hit a little snag.

The bike came stock with
Chain - HG-53
Crankset - FSA Vero Compact
Cassette - Tiagra CS-HG50 11-25

Then I added the Sram Apex Compact (designated 10 speed) crankset and everything was running smooth, until I picked up a crazy cheap Dura-Ace CS-7700 12-21 cassette from NashBar (Mostly flat here in El Paso) and now im not only getting a weird vibration on every crank but now i hear a click as if the chains outer plate is a little too wide and hitting the hyperglide teeth.

I understand the HG53 is the basic chain but I figured that all shimano 9 speed cassettes were similar in outer width. Now im reading that the dura-ace 9 speed chain is "super narrow" for narrower cassettes

Fortunately I was gonna pick up a new chain anyway but now I'm confused on which one I should get.
Obviously I was leaning towards the KMC X9 SL but will it be narrow enough?

Luckily I installed the cassette today and was only running through the gears on the stand so I didnt damage any teeth so any help would be appreciated.