Isn't the DD ruler/combo only 12"?
If that's enough for you, then get it (especially if you can get it at Joann's with a coupon).
The older (discontinued) Fiskar's model was 24" .
The only other 24" combo on the market that I've ever seen is the one by Sew Easy Sew (from Australia, I think).
Pricey, but it works well.
I bought mine here:
http://webstore.quiltropolis.net/sto...3&Item_ID=8117