I think I can answer a couple of your questions but I think more important you have to ask yourself a couple of questions.
What kind of tank are you wanting to have? (I know I know "I want it all"!)
The livestock you currently have is not very conducive to a reef tank as they are big and messy eaters so chances are you are going to constantly battle nitrates. Corals, anemones etc. do not like high nitrates and for the most part do not do well. While zoos, zenia or anthelia, mushrooms will do OK IMO it is usually the duller coloured ones that seem to thrive and not those nice bright little buttons.
Bioballs would be fine if you want a FOWLR system and in fact are quite good to have in these systems however they do tend to collect crude and therefore contribute further to your nitrates. Again you have to ask yourself what kind of a system you want to have.
As for the transfer, if your existing tank is well established you should be fine just transferring the live rock and livestock directly over - try to get as much of the water from your existing system to transfer as well. What I would do with the sand is to rinse it really really well with RODI water and then slowly transfer that as well making sure to constantly check the new tank after each small addition to make sure it is not causing a cycle.
HTH