Lol I know right...it was much harder for me to find out info on HID. Had to read a lot of grows to get an idea of what to do and what I'd need. What you linked looks just like the fan I have, but yup, that's what you're looking for in general. Usually, the lights come with hangers...but I think it has been easier for people to mount it in small places and just raise the plants close to it if they need to be. And yup, you'd have the inline positioned at the same place you have the exhaust...I'd imagine in the bin that you'd probably be able to connect them right to each other with minimal ducting if any at all. 6in tube to 6 in fan is correct. Same with ducting.
Just thought about it, it' probably be a pain in the ass to open the bin with the light hanging or being mounted. IF you did think about a little cabinet, the only DIY you'd have to do is to cut intake and exhaust, then a circle in the back to feed wires through. I think I've heard people saying they take things to lowes to have them cut? Hell, you could probably build the box cheap as hell after you have Lowe's cut the dimensions you want. I know I know...you don't like DIY, but it's not that hard to just make a square box...that's IF you think about switching.
You're right, the cooltube isn't air tight. The end that houses the socket is left open to draw air across the light, and passive intake works well. I don't need anything else for intake even though the tent is 4x4x6.8. You will probably only need ducting if you plan on raising and lowering the actual light.
Lol I'm far from an expert...but I studied the hell out of it like a true nerd
. I don't mind looking around for you at all
Now the ballast question, you might want to look that up because I'm not entirely sure, but I believe you can run a 150 on a 250 ballast with no issues. Manufacturer bundle is better to me because it comes with reflector, lamp, bulbs, ballast, hangers, and timer! And if it's a good bundle, warranty