Cidly Aquabar conversion, heatsink ?s...

These are some cheap chinese Cidly Aquabar LED strips using 3w diodes and currently consuming about 45w, passively cooled. Planning to convert a few to COB. Gonna remove the circuit board the LEDS are attached to at the bottom. Width of the board is 25mm, CXB2530s just fit! These are 36" heatsinks but Im not sure how to calculate the surface area for heat dissipation, its not exactly a size thats easy to measure! Also wondering if you use more fans, can you further reduce the surface area required for active cooling? I was thinking about running 4 cobs / strip at 650mA. This should take about 94 watts of electricity, figuring 47% efficiency that would leave about 50w of heat to dissipate. Im planning to run 2 fans / strip, spaced equally between the cobs. Nice thing about this heatsink is there is a nut holder built into the top, so it will be very easy to secure the fans and the drivers. Would it be better to place the fans directly over the center cobs or equal distances between them? Thoughts, ideas, opinions and suggestions appreciated!

What ever became of this project?

They work good for cobs and strips. I've put up to 30w / foot total energy into them and they cool fine at room temp passively.

Thanks! You have given me some ideas. I have one of their micro spectrum versions, and I'm finding that I don't need the IR and UV diodes. I don't know what chips they used originally, so your retrofit will be handy if I decide to just change up the whole thing.