My RAT-7 came with a excellent 7" Spec-Ops Brand sheath.(circa 2008-9?)
(I still have the sheath as I use it for my Randall 14 user.)
Spec-Ops make a Combat Master Long (In Black,Coyote Brown or Multi-Cam) which will take up to 8" blade,so the RAT-7 fits nicely.
Liners are available separately.
Check them out.