Spring stats are worthless, but I think anyone would prefer good stats to bad. Even if it is spring training, Redding looks like a decent gamble for a young arm or 6th SP. I'd take a chance on him over E Jackson I think at this point (although I won't be dropping Jackson for Redding personally).
I'd pass on the others. Ishii maybe is worth owning, but his WHIP potential scares me away. I'd take Redding or Jackson, Redding probably getting the nod due to his nice spring.