What defense do you run?
I run a 4-2-5, so the LOLB position is almost never on the field. Leader Miller is a fantastic card (awesome speed) but if he's only playing a handful of snaps a game, then you aren't getting great value there. If you are you running a 3-4 or a 3-3-5, then he'd be a great pickup.
Who's your 4th corner? I personally like Deion better than Pat Peterson or any other corner not named Woodson but I'm not certain he would be a huge upgrade for you. You need 4 capable corners though.
As for getting CE Howard - it wouldn't be the worse move in the world as long as you running a lot of 4 or 5 wide sets. I think Elite Randy Moss and CE Crabtree are better WR's but Howard does have value.
Leader Sapp is an option. He's been a surprise to me. I didn't expect much more production out of him but he makes a fair amount of plays. DT isn't a huge value position though.
I'd hang onto some coins too - as long as EA is releasing new leaders your much better off buying them the week they are released. I'm expecting a Leader Jarvis Jones, Randy Moss, Barry Sanders , Deion Sanders, Peter Boulware and more.