I had to make essentially the same choice, also liked the ML03, but my full-height Colossus card wouldn't fit, so I chose the GD04 (same case as the GD05 but with the "stealth" optical drive cover. In my view it looks much better and more "finished" when done than the GD05. I recommend you look at that rather than the GD05).
I think the Ceton is half height so it will probably fit in the ML03. And you can probably cool it ok. But with heat comes noise. And it is inevitable that three 80mm fans will be noisier than three 120mm fans while moving less air. Indeed, you're planning on FOUR fans plus a PSU fan. Good luck on keeping that quiet.
Also, not sure about the ML03, but I'd recommend against a modular PSU on the GD04/05. The cables tend to stick out farther on modular cases, and in those cases you need to bend the cables pretty quickly because the space between the PSU and hard disk is limited. It's more important, in my view, that you pick a 5.5" deep PSU rather than a 6" one than it is that you eliminate unnecessary cables. That extra half inch in between the PSU and hard disk makes it easier to build, and there is enough room to store unused cables. Cable storage room may be more critical and argue for a modular in the ML03, but someone who has used it would know better.
BTW, I use a FSP Aurum Gold 400 PSU in my GD04. Works great.