You're on the right track, I can tell you'll do better with LEDs than most.
I'm currently assembling my LED stealth box retrofit so I have little experience growing with LEDs (15w bloomboss spot to test the waters) however I can give advice based off of what I scraped from across the internet these past 2 years. Take it with some salt of course. Most of what I have is coming from too many sources to cite but you'll find the applicable information if you google around enough (It's best to get information first hand from research papers anyhow) and ignore what the companies that sell grow lights say. They are marketing people, not botanists.
You should be good with your blue/red ratios. Red can be less specific of a frequency than blue however both can vary widely from the "optimum" frequency and still maintain good performance. Focus first on which LED will provide a higher luminous flux and then on what is closer to optimum, especially in red.
As long as you keep within the peak range of 450-475nm for blue and 575-675nm for red.
LEDs in that frequency range are common and cheaper/more efficient than trying to get an exact frequency. Trying to get the absolute perfect frequency is like losing a race because you spent the first hour mixing your fuel at the starting line for an extra 5% speed boost.
I'm sure you know that more than just two frequencies are important for the xanthophyll and carotenoids however your 6 white LEDs should be plenty to cover that and I concur with your color temperature choice.
I went with CREE XPE LEDs for the red-orange and blue and CREE XPG for white in my box. Those I found after a couple months of on and off research to be the best balance of energy efficiency, PAR, and cost.
As far as your far red I feel you're planning on using waay more than you actually need. I've seen people help flower their outdoor plants by "spraying" their plant with near infrared by just shining it across all the leaves for a couple of seconds each day with a handheld light. You only actually need just a few and can fill the rest of the light with whatever cheaper red you're using.
You should click here and check out this experimental grow going on in Amsterdam. He used only 2 far red I believe and that greatly shortened his flowering time. His name (or at least what he goes by) is Hans and he has been doing grow after grow and making frequency, diode, amperage, cooling, etc. adjustments to his grow panels and has since out performed conventional HPS for yield per watt hour. I don't agree with his non-scientific approach; it lacks control groups and the information is poorly organised. His findings and methods do however match up with what information I've found across the internet to be true and he is getting real results, not just theory and hearsay like you find anywhere else. He also believes all of the store bought LED lights are worthless though I have much harsher words for them(and those bastards almost had me believing LEDs are a gimmick that will never be useful for growing). Read his results from beginning to end to get the whole picture.
UV, ah the Underestimated Violet. If you try to implement UVB into your grow without undue cost I'd say go for it. The current theories are that UVB either converts CBD into THC (Lydon and Teramura 1987) , UVB damages the plants cells and in response it creates more resin (THC absorbs UV), or that plants which evolved in high UV climates have higher resin content in much the same way humans have melanin (Pate 1983). Nobody seems to have anything but anecdotal evidence and theory that it actually works but most signs point to yes. I'm going to put a repti glo CFL in my box and have an external switch to cut the power and prevent accidental exposure. I strongly advise you to do the same if you do try this.
I've been taking pictures as I'm upgrading my box and I'll probably post them on RIU if you're interested in seeing how it works out for me. Just PM me so I remember to tell you when I do.