I'm definately not the guy you want advice from for IDP (10th of 12 my only time playing in one). But our settings were 1 pt per tackle, .5 per assisted tackle and 2 per sack and int.
This appears very IDP friendly so I would draft one of the 2 guys listed above.
Lets break it down.
Wash plays a 4-3 with Orakpo playing the Strong Side LB. He is right next to Haynesworth so he might get some easy sacks due to being covered by a RB. I'll quote MattB47
Linebackers are pretty straightforward generally speaking. For the most part you can bet on guys playing MLB and WLB (Weak side LB) racking up the most tackles which makes them the most consistent guys in all of IDPs. You will normally want guys from these positions in the 4-3 as they will more consistently get in on a lot of plays. Something also to look at is the scheme they are in, the guys who play in the Cover 2 schemes (such as Indianapolis, Tampa Bay, etc) generally have very productive MLB and even WLB when it comes to tackles.
GB plays a 3-4 and Matthews is expected to start at right outside linebacker, ahead of Poppinga, in the Packers’ new 3-4 scheme. They have him listed as an ILB on the depth chart. This will be key because players that are listed as a LB will sometimes play both DE and LB and they are sometimes given DE eligibility. (Learned this from MattB47 to) The problem is there are already 2 stud LB's on that team in Hawk and Kampman that might gobble up the sacks and tackles.
With those 2 in mind and Matts advice I would go Mathews. But Orakpu is real close and might do very well this year.