What size axle are Jekyll swingarm dropouts (specifically swingarms compatible with my frame for Uber V purposes)? 10mm or 9mm?

Here's my current situation: I have to return this Mavic Crossride Disc Thru Axle 26 inch wheelset Mavic Crossride Disc Thru Axle 26" Wheelset 2013 | Mavic | Brand | www.PricePoint.com. Only the front wheel will fit my Fox front shock which has a 15mm thru axle. My frame is a 1999 Cannondale Super V 700 SL. Pricepoint rep told me 10 or 9 x 135mm standard quick release will fit my frame & if it's 10 make sure it's QR because 10 also comes with thru axle. He also mentioned I could keep the front & sell/trade the rear, but i'd rather have both wheels the same make. But if I do change my mind & keep the front & sell/trade the rear, how easy or difficult will it be? My Crossride's are entry level, brand new, never installed but not sure how wanted they are.

I'm thinking if the Crossride 12mm rear axle fits compatible Jekyll swingarm dropouts, then I may keep the wheelset if I ever get a Jekyll swingarm. Currently I still got the stock Super V swingarm. If I keep the wheelset, for now i'll just use the front wheel & buy a rear wheel 9mm/10mm QR. Thanks