Skimmer is essential. Check out nano-reef.com and use the search function to
find the thread on fitting one into a deluxe.

For maintenance, this is what I've gotten for mine in the past 6 months:
ph probe
test kits (Ammonia, Nitrate, Nitrite, Alkalinity, Calcium, Phosphate, ph[bought
before the pen])
calcium additive
reef epoxy to stick corals on with
a bag of carbon
fish foods (frozen and pellets)
plastic syringe for feeding w/airline tubing
swing arm salinity gauge(in the process of buying a refractometer)

Mmmmm, that's all I can think of ATM.
~John