I put Corbeau seats in my 2011 Mustang. They are owned by Recaro. $300-400 range for the seats and another $100-150 for specific brackets.
Be prepared for airbag error codes if you use aftermarket seats. I disassembled a set of Mustang seats, got ALL the airbag stuff out of them and installed into my new seats. Pain in the bottom dollar, No codes!
I understand there are some plug-in airbag test modules which override the codes.
csm