Disk Brake- Flat mount to IS mount?

I'm looking for some help. I bought a RS-505 (105 disc) groupset. It came with flat mount calipers. I'm putting them on a Soma Wolverine which has a international standard (IS) mount. Is there an adapter that will fix all my problems? Or do I need new calipers. If so, which IS mount calipers should I buy to go with my RS-505 shifters?

Thanks for the help!! 

You'll need to buy the correct adapters for your rotor diameter, front and rear. I'd go with the Shimano, but there are lots of options. 

GuzziBen wrote:You'll need to buy the correct adapters for your rotor diameter, front and rear. I'd go with the Shimano, but there are lots of options. 

The problem is there is no adapter to go from flat mount to IS mount. 

I actually sorted this out a while ago and never updated the thread. I had to buy new calipers, RS-785, which are post mount. Then buy Post to IS adapters like any MTB setup. 

Thanks for the suggestion though.