When it comes to the flash unit, I come from the school that if you're gonna spend the money, there's probably a minimum that you're gonna want to go for, or else you might as well wait until you can go for it. In this case, the minimum, IMHO, is ETTL functionality.
There's nothing quite like having the flash unit be compatible with the camera so that your exposures are dead nuts.
So, if you decided against one of the Canon flash units, at least get a unit that somehow communicates with the camera.
I just sold my 430EX to Ted for $175. That might be more than you're willing to spend, but I can tell you from personal experience that your wife would be EXTREMELY happy with this flash unit.
I was skeptical also at first, but I was impressed enough with it that the reason I sold it was to pay off my recent audio purchase, but I felt it was expendable because I'm gonna upgrade to the 580EX, which goes for $350 or so. Ridiculously expensive, I know, but based on my experience with the 430EX, I know it will be worth it.