Mac+ATV+Time Capsule+Hard Drive

Hi everyone, I need your help as I am unable to find the best setup for all my gadgets. First of all, I was using VideoDrive to move the files to Itunes and it was transferring to Apple TV. Now the apple TV as 75% full so I bought a 1.5TB external hard drive. I sill have another 500GB external and a Time Capsule 1TB.

Ok so here I am, I don’t watch movies in Itunes on my Macbook Pro so I don’t have to keep them locally. I realized that I need to keep files in .avi if I want to use them in XBMC on ATV because once altered by Videodrive, I can’t play them anymore.

I don’t really care about ATV built in video software but I guess I should use XBMC so where should I keep my files? I have to keep in mind that I will not be able to keep all videos on my Macbook cause I have a 500GB internally.

For now, I switched the ATV primary drive to the pluged in USB 1.5TB but I can’t access this content on XBMC. I am simply unable to find de best solution. Maybe if I switch back the ATB to internal storage, plug the 1.5tb on my Time Capsule (NAS) and use XBMC?

Anyway, your input would be appreciated.