What gauge strings for Drop-C tuned 5-string bass?

Thorax the Herdsman

Procrastinating Fuck
I'm a guitarist but using our (ex-bassist) vocalists 5-string for recording the bass parts on our upcoming EP.

It's currently set up for standard 5-string BEADG tuning but I want to tune it down to drop-c - so CGCFA, to match the guitars.

What gauge should I use? I'd prefer them fairly tense but so long as they're not flopping all over the place I'm not too fussed. Thanks for any info!