Since you are going reef I would really suggest getting the best skimmer you can for the money you have budgeted. A skimmer rated at double your tank volume would be a good place to start. So one rated for 125g to 150g would be my first purchase.
What do you have for filtration? Circulation ie: powerheads? Lighting?
A great idea is to get yourself a refractometer for testing salinity ($30 on ebay) and a good liquid test kit.