I built a similar
quad-P7 running 2p3s 17670s.
I used triple Sharks sharing one pot. Not an easy mod, but it works well and is seamlessly dimmable from 2.7A to zero. The Sharks need to be well sinked. They get hot at that level of boost, nearly 100% (Vin/Vf), and are not particularly efficient in that range, but it's certainly not a light I built with efficiency in mind.
Be prepared for some serious heat generated by four P7s running at spec. It's the second hottest light I've built, the first being the
Moby **** Trinity (tri-Ostar + tri-Cree) driven by the same Shark setup.
You will probably need more than one driver unless you have unlimited space and can fit something huge. And if you want dimming, they need to be capable of sharing one control. That limits your choices of off-the-shelf drivers.
The Sharks are compact and I could fit up to 4 in front of a Mag D switch with heatsinks if needed. Usually I use 3 and a pot and though tight, it all fits comfortably. For high power lights, I add heatsinks cut from brass shapes to the top of the IC and a dog leg on the diode. Here is a pic of the running gear for a Trinity.