Ambitious project, I like it very much.
However, the lamp will be twice as expensive as if you build them with F-Series strips. To squeeze out +200lm/w the Nichia 757 needs to run at 65mA, which means you need a hell of lot of sol-strips. I was facing the same question a quarter year ago and chose LM561c running at ~60mA (525mA per strip / 11,8w) because F-strips perform better than Q-strips when running with the same current. Nichia strips were not available to the date and I did not want to wait.
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You have to think about how much the efficiency jump is really worth to you. A 10% more efficient lamp is likely to cost twice as much and it takes longer to recover the cost over your electricity bill.
Even my lamp is actually way overpriced when one looks at it from the standpoint of dimnishing returns. Instead of 20 I could have built it with 10, would have paid half that much but still get 175lm/w.
Your heatsinks look good, no question, but if you actually drive the sol-strips with so little current, then they are unnecessary. A simple frame would be enough to fix the stripes without any heatsink. A heatsink is only necessary if you drive the sol strips harder, but then you get no 200lm/w. And this is where the F-Strips come in again!
What would it cost if you want to get the same price/performance as an F-strip?
Let's take the 187lm/w at 60mA from the example above(cost are 14$/2ft.strip, 11,8w, 187lm/w).
How low do you have to drive the Nichia 757 to be better than that and what does it cost?
If you plan to use them for the next 5-7 years, okay, then the costs will play a subordinate role. However, if there is something better in 2 years and you already look in that direction, then you should look at it from the price/performance point of view.
Shipping costs, VAT and customs are also things that must be considered, usually you need to add ~25% for euro buyers.
Do not get me wrong. I would really like to see you finish your sol-strip project. Would certainly be one of the best in the DIY market. Just be aware, you will have about twice the cost for such an efficient build.
BTW, the link to the sol-strips is not working
i do definitely prefer the white light though.
and second i want a nice looking and solid diy stuff, i really think led growing is going on this direction for limited height or multilevel growing space, with those new led/driver we can have the light penetration....and finaly im kind of fetishist.... i want the best 
