Unless you have other implements that use flat face bobcat style couplers, I would recommend the regular "pioneer" style couplers. Tractor style couplers will be much cheaper and work just fine. If you plan to rent equipment which frequently use flat faced couplers, then I would go ahead and just put them on the tractor side. The flat faced come in styles including pipe thread and o ring. Sizes can vary from 3/4", 5/8" and 1/2". You may need to get adapters to fit to the tractor side depending on the size and thread type. Most flat faced couplers will run $50-60 each. Tractor couplers in the $10-14 range.
I also made a set of adapters with flat faced couplers on one end, a short adapter, and then tractor style on the other. (Use these mostly on the rear hydraulics). The adapters are easy to make. I used flat faced couplers with 1/2" pipe thread, mated to male/male 1/2" adapter, and then 1/2" pipe thread tractor style couplers. The flat faced couplers need to be one male and one female so it can match rented equipment. The tractor side will depend on the couplers on the tractor (male/female or male/male).
The biggest advantage to flat faced couplers is much higher flow rates but this is not an issue on tractor hydraulics.
