Price-wise be sure to compare final configurations again the Core i7 & i5 CPUs. In some cases stepping up from the Core 2 Quad may not cost much and may be a significant boost in video editing.

Skip RAID get a big NAS (2x or 4x the size of the computer storage) and Acronis TrueImage software for backups.

(RAID is not a backup scheme)

HP, Dell and the the others are just re-badging OEM junk in a lot of cases these days - it's hard to say who makes it any more. My last Dell notebook and desktop weren't made by Dell...