well, i don't know about cuff links, since i don't wear them, and unless your boyfriend is always in suits and whatnot and actually wears cuff links, or wears them often, i would say scrap the cuff links idea. Though I don't know your boyfriend, it's just that usually cuff links are, IMO, the one men's accessory that gets used the least.
also, "financially well off" could mean different values for different people, that being said, perhaps you want to give us a little more info on how much you're willing to spend?
eitherway, i'm sure your boyfriend will love whatever you get him, mostly because it came from you!