Just in the process of making a system of my own. Won't be quite like that, but I have the 30k galvos on order and I will be going for the Pangolin FB3 for the DAC with 200mW Red, 100mW Blue and 50mW Green.
Damn this hobby and SenKat ;D Only came in 2 months ago to grab a few LDs from SenKats GB and now I have been sucked in grrrrr ;D ;D ;D
Actually, for a good white balance the 100mW or 532nm and 472nm will work decently. At those low levels though, you'd want to up the power on the 635nm. Personally though, I'd save up the extra $$$$ for a matching 671nm. 635nm will be cheaper for the beam sources, but you'll end up with a beam 3-5mm thick and 3-5mRads of divergence (or trade off between the two as you like) because of it. That probably means you'll also have to buy optics to expand, and improperly collimate the green and blue unless you want to have those sources that are a thin cyan beam with a thick red splotch around it.
On the other hand, find a 532nm 473nm and 671nm DPSS that are all matched well for beam specs and all you need are dichros and an upcollimator and you're ready to go with a FAR less diverging beam. You'll get a larger color gamut too!
(at a cost, no doubt, but I figure if you're gunna spend that much money on something, you might as well do it right. That's why I can't afford to build my dream RGB yet )
The best "white" projector there was 140mw of green ( I think it was a 250 module and his first mirror was a dichro and he lost over 100mw on the first jump ) 130 mw of 473 and 380mw of 660 red coming out the business end checked with the lpm1 and a lasercheck ( they were within a couple mw of each other although you need the nd8 for anything over about 80mw or it reads low )
The best looking projector was ~140mw of 473, 230mw of 635 ( 250mw multimode diode, looked AWESOME ) and I don't remeber how much green.
I have a good comparison pics and some vides of the 250mw 635 vs the 400mw 660 and the 635 blows the 660 away even though it's half as powerful. the higher power of the 600 though did make a better color balance and a "purer" white.