I don't see any reason to get Leonard; he'd be redundant with KO and would cost more.
Beasley would be interesting if the Celtics could get him for cheap, but I think enough teams have an eye on him that he won't be a bargain unless he produces close to the tune of his pre-draft hype. I'd take a flyer on him though if he can be had for a short deal at less than $9 mil a year, especially if trade options continue to fall through.