Yep, you'll be fine. As long as any sand you take from your current tanks doesn't smell like rotten eggs, you shoud be able to use as much as you want. You might consider taking the top couple of inches. It would not be a bad idea to get some seed sand from a few other sources; inland aquatics sells "invert sand" that's pretty good, plus you could get some extra worms.

I'd still consider letting the new system mature for a few months before adding any fish; it will really help your infauna population to grow.