I'm in a league like that. I drafted McGee in the 8th last year as the 3rd defensive player off the board. A couple of years ago, I picked up Azumah off the wire when he starter returning kicks. In both cases, they became my best defensive player. Last year I won my league in large part because McGee put up 30 points in the championship game. So if your league is rewarding return yards at .1ppy, snap up every defensive and offensive returner you can get your hands on.
Last year, McGee scored 195 points on my format (1/15 return yards). By comparison, Vilma, the leading tackler last year, scored 173. On your system, McGee's total goes up to a staggering 241 points, which is far above any non-returner defensive player could hope for. You'll have to determine whether anyone else in the league knows about it to figure out when you should draft them. But it's a good idea to start pretty early (say the 6th), as other owners will certainly catch on to what you're doing at some point.
The key is to get a guy who both returns kicks and has decent tackle numbers, if possible. A good defensive KR/PR specialist nets around 1,700 yards, which is probably about equivalent to a top defensive player. But a KR + tackler (like McGee) takes it to another level entirely.
McGee is the clear-cut #1 guy. Jones and Miller are 2a and 2b, but watch Jones' situation. A high 1st round pick usually doesn't end up returning kicks for too long. Carr is probably 4th at this point.
Other people who stick out:
Devin Hester - rookie return specialist who should see action quickly as KR/PR for the Bears
Allen Rossum - injured last year, but generally handles all of the return duties for the Falcons
DeAngelo Hall - if Rossum doesn't return kicks, Hall probably will. One of them will be valuable.
For returners, much more than other positions, it's important to keep up w/ depth charts right at the beginning of the season, since thoseduties tend to shift a lot more than other positions.
If your league rewards return yards for offensive players too, there are a ton of very valuable players that can be had as well:
Dante Hall
Jerome Mathis
Darren Sproles
Reggie Swinton
Wes Welker
Eddie Drummond
B.J. Sams