Well, I've finally made a decent amount of headway with the front panel mods. First things first, the rad had trouble fitting with the holes because it was being propped up ever so slightly by the piece of metal on the underside of the front panel itself.
A little Dremeling later and...
Ahh. Some filing and grinding and...Much, much better.
In terms of the front panel mods, what I did was cut out a fair amount of the honeycomb so that the radiator had some more breathing room (while making sure to leave the mounting holes in place. I then got a nice piece of dark gray smoked acrylic and cut it to fit flush within the front bracket that I had previously modded, and made the same radiator-accommodating cut-outs. Finally, I added a white Phobya rad grill, with the front part on top of the front panel and acrylic, and the actual grill part between the top panel and the rad. The end result has a cool 3D effect that I think is really nice.
Not sure about the screw caps. I really like the look of some clean socket-head bolts, but these caps' color matches the rest of the build almost perfectly. Any thoughts?
As far as the INSIDE of the front panel goes, I have another coat or spraypaint to go, but I wanted to try it out and see if everything fits. Here's the rad mounted to the front panel with the Corsair SP120 (Quiet), some fan grills, and, on the top one an Alphacool reservoir mount. Looks like it all works.
Finally, I mounted the 280 rad to the Koolance shroud and modded the top so that it fits on there. It pretty much takes up 80% of the real estate including the entire depth of the case, and I had to re-do the cuts a couple times to make sure that the radiator itself is accommodated, since it sits a little bit up in the shroud. I've got some Noiseblocker BlackSilent Pro PK-2's between the shroud and rad itself.
Pretty happy with how things are going. Tomorrow, I'll do some sanding (P600, 800, 1000, and 1500) and then painting to get a nice finish going on the case, then put everything together and hope to heaven above that the top rad and front rad play nice.