Five would be great! They'd be loving life in that huge tank :}
Make sure the pots aren't sharp! You can find a lot of ceramic hides at pet shops just be weary that it is a) not sharp - run a stocking a long it to see if it snags b) no little holes they can get limbs stuck c) doesn't move - they can snap at it or get hurt by it clamping down (referring to bubblers) and d) aquarium safe!
In my tank I have a little terracotta pot with plant rooted to it, smooth drift wood and a 3 pipe pyramid. I'm still waiting to make a small shelf hide thing (two small rocks x-distance apart with a smooth flat top on it). The shelves are also a good idea! I'm waiting on some materials to start making them.
I've seen mugs, teapots, driftwood and PVC pipes used too which is pretty cute! Have a browse in the "picture of your tank" thread for loads of inspiration.