You still didn't mention run-time but for the purpose you described I would think good run-time would be helpful. Looks are a bit subjective so from that standpoint I can't give you any more input. With regards to focusing only a few lights have that feature that still fall within your other parameters. Actually, I think there's only one type, the Oracle or Tactical HIDs. Since the run-time on the 24W is so short that only leaves the 35W, which most owners seem to like.
After having owned a light similar to the Oracle 24W, I can say they're not nearly as useful as work lights as the N30 or L35 style lights. Also, I never use the focus on focusing lights...I always just "set 'em and forget 'em" as Ron Popeil would say. A diffuser on the other hand, I find to be a useful accessory.