5160 will work fine.1070 or 1080 will also be good choices.Wally Hayes has a very good video set called,"KATANA",that is worth the money.It has good info on stock removal of swords,and good HT info for those without a 36" HT oven.If this is your first foray into long blades,I would highly recommend this video set.
(There is a site you can rent knifemaking videos from - technicalvideorental.com )
Stacy