From my understanding of what's available, hondata s300 with hondata's COP kit is going to be what you want. It's all meant to work together and seems to work as well as one could imagine on an oem ecu. Any other option worth doing will require a stand alone ems.
Maybe one day Dave Blundell will finish his kit, then you could use Neptune, or maybe even Crome. Hondata won't give Neptune the permission/info to use their kit without a boatload of money. That's been discussed on the hrtuning forum multiple times.