The 2017 Easton MAKO BEAST BBCOR Baseball Bat: BB17MK and the 2018 DeMarini CF Zen BBCOR Baseball Bat: WTDXCBC are very comparable options featuring two piece composite designs. They will have a very similar feel and the balance of the two options are extremely comparable.
Bat recommendation will vary from player to player. If your player likes two-piece, composite bats with a balanced swing weight, then I would recommend the 2017 Easton MAKO BEAST BBCOR Baseball Bat: BB17MK in a 32 inch length. However, if your player likes one-piece, alloy bats then I would recommend the 2018 Easton Beast X Speed BBCOR Baseball Bat: BB18BXS in a 32 inch length as well.
BBCOR bats like the 2017 Easton MAKO BEAST BBCOR Baseball Bat: BB17MK can only be used in the 'Senior League' division of Little League. You will be approved to use this bat if you are playing in that division. If not, I would recommend something similar like the 2018 Easton Ghost X -5 USA Baseball Bat: YBB18GX5 which features the new USA certification for Little League.