I'll just jump right into it. I believe there are 10 players the Cowboys are targeting in the first round. I also don't think they are putting an emphasis on any one need.
1-David Decastro, OG(at least he should be #1 on the list)
2-Fletcher Cox, DT/DE
3-Michael Brockers, DT/DE
4-Mark Barron, SS
5-Courtney Upshaw, OLB
6-Dre Kirkpatrick, CB
7-Dontari Poe, DT
8-Stephon Gilmore, CB
9-Peter Konz, C
Now I think Decastro and Cox will be gone by time it gets to Dallas 14th pick, leaving 8 players on their 1st round board. To me, this means they can drop no more than 7 spots to land a player on their list. I believe they trade down because again there doesn't seem to be one specific area they are looking at, and for some reason Cleveland at 22 overall seems like a good partner, and it drops Dallas exactly 7 spots.
So now trade scenario, Dallas trades with Cleveland down to 22. Dallas also gets Clevelands 3rd and 4th. Dallas later trades their 3rd round pick, with the 4th round pick they got from Cleveland to New England for their 2nd round pick at 63rd.
On to the mock. By time it gets to Dallas pick at 22, as I mentioned Cox and Decastro are gone, along with Brockers, Upshaw, Glenn, Kirkpatrick and Barron...leaving Dallas with Poe, Gilmore and Konz left to choose from at 22. I think they'd go with Poe, just based off of rumors, they do want a DT, and fills a need/depth. It wouldn't be my pick, if it were between Poe and Gilmore I'd take Gilmore, but I think this is what they would do. As is with the picks.
RD1(from Clev, 22nd)-Dontari Poe, DT-Memphis
RD2-Dwayne Allen, TE-Clemson
RD2(from NE)-Ronnell Lewis, OLB-OU
RD3-Ryan Broyles, WR-OU
RD4-Brandon Taylor, SS-LSU
RD4(comp)-Philip Blake, C-Baylor
RD5-Emmanual Acho, ILB-Texas
RD6-Chris Greenwood, CB-Albion
RD7-Ronald Leary, OG/T-Memphis