[Closed] lightweight chainguard for a 1x9 commuter and other early morning questions..

I'm thinking of converting the commuter to a single ring (1x9 with maybe a 40ish ring...)

Rather than fit a mtb-style chain device I figure a lightweight chainguide would look better and do the job.

I've seen these (use one on my mtb)
http://www.bbgbashguard.com/Cyclocross.html

but any others out there? Could go carbon, or hell even placky?

Also, would you fit a guard either side of the single ring, or just the outer position?
If just on the outer position then what stops it dropping on the inside?
Commuter gets taken on on the odd towpath so needs to be solid.

[110mm BCD crank]