Hello Marcus, the XPE, XPE2 and XTE whites have been outmaneuvered by the XML2 whites and the Vero 10s in terms of efficiency and price. As far the Oslons go, only the deep reds are competitive but the Luxeon ES 660 can match it. The best blues are Luxeon ES royal blue M4R. The best 630nm reds are the Cree XPE and XPE2 P3 bin. Are you in EU? If so the Oslons may be easier to source.
All that said, building RWB modules is a lot of work, more expensive and less efficient than COB all-white setups, so that would be my best recommendation for a 4X4 flowering tent. Good luck!