The best resource for you right now would be nano-reef.com Particularly the lighting, DIY and AIO forums. I bet you can find lots of threads regarding DIY retrofit for your tank there.
Ray at Aquastyle Online will answer emails or comments submitted through the website very quickly. He appears to be fluent in English so no worries about language barrier and ask how to switch some emitters colours around when ordering, he will accommodate.
I only started SPS since getting the aquastyle LEDs so I can't offer comparative advice but the SPS I acquired since are growing well.
The voltage and emitter questions will be well answered by the fine folks at NR, it might be worth you cross posting there if you are not getting the answers you seek here.
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