IDP Replacement Help (McCarthy/Harper)

[T-Lo]

Hey guys, I've been a long-time FF guy but:
1) I didn't take it serious until recently.
2) My main league switched to IDP last year.

This looks like a good place for advice/FF talk.

Here goes, I have two main issues directly relating to IDP. Players are currently on waiver for my league, or I can wait until they go FA. Last year we switched to IDP and the week of the draft I lost my internet connection. My team drafted yahoo base default rankings and my DEF was crap. Me picking less great players left higher quality for the others, so most of the top LBs and other top positions (Jared Allen) are keepers and unavailable. Last year I did not take the time to pick up better free agents until it was too late. In all reality, I'm a rookie FF player even with years of play.

Here is my DEF:
DB (CB) Patrick Peterson*
DB (CB) Jason McCourty*
DL (DE) Mario Williams
DL (DE) Julius Peppers
LB Brian Cushing
LB Lance Briggs

Back-up:
LB Stephen Tulloch
DL (DE) Kamerion Wimbley

* - keeper

Question 1 - DB) Peterson & McCourty are decent and (I feel) have a good upside. SS Roman Harper is available (as well as Pollard, Burnett, & Chung but they aren't as high quality to me). Is Harper a definite pick-up from waivers to replace Peterson/McCourty? If so, who should I cut? Also, I could replace one of my back-ups with Harper instead.

Question 2 - LB) LB Colin McCarthy is available on waivers. Similar to Q1, he is very valuable yes? If so, should I replace Briggs or Tulloch? I feel Cushing is the keeper of the bunch.

I have logic in my mind for what I want to do, but I have no football fans I actually know. All my football friends are people I know online, I wanted your guys opinion.

[colveraki]

I've been in IDP league for about 7 years now and my league plays IDP differently than yours, I have found that it is still a little easier to find talent for defense than offense. A good player that might be available is Jabaal Sheard. I do like McCarthy better than Briggs. ESPN has decent IDP rankings.