Sounds like a good plan. The otto's are pretty sensative. You need to be darn sure your tank is cycled and there is plenty for the otto's to eat.
I have had good luck with them before until my Creyfish at them all lol. Oh sure the fish store said, they are fast enoughm they can get away... 15 minutes in my tank he had one in his claws.
As for cycling, will snails help cycle it or no? I am leaving for vacation in 10 days and I dont want to have to wait almost 3 weeks to start cycling it. I mean hey ya gotta do what ya gotta do but you know... patience isnt my best virtue