I've got to advise soldering things together. Solder less is neat in concept, but the contacts will eventually corrode and either lose contact when jolted, or simply lose contact some day.
With today's lead free solders, corrosion should never be an issue. LED stars are easy to solder to.
Depending on your heatsink, a fan probably won't be necessary. I use two panels of 12 emitters running at 670mA on my 70g. It gets warm enough that you can feel it if you touch it, but only just warm.
I used a 50/50 mix of warm white and cool white. I like it and so do the plants.
You may not want optics on the emitters on the ends. Try it with and without.
One very important thing, Post a picture and details when it's done. Lots of folks will benefit from your experience. Even those of us who've gone LED can benefit from the experience of others.