fly into denver, if you want a cheap place to stay you can get cheap rooms west of denver for 29 dollars a night. from there its a 1hr drive to keystone and breck...however the traffic can be really bad.... anywhere closer will be A LOT more expensive..
if money isn't much of a problem then you can find lots of nice places to stay outside of breck and keystone. Both places have nice parks, keystone has 3 parks, and a lot of variety, and breck has one big park. Also the same pass is good at vail, breck, keystone, and A basin, so you can ski at one of those places during the day then ski at keystone during the night. however i dont know much about the conditions in april. also breck has better all around terrain then keystone.