Geweagle
The biggest and hardest thing to do in this hobby is to be patient it can take a few weeks to a month or more for stuff cycle and it can be annoying as hell watching a virtually empty tank do next to nothing and the itch to put something in there can be unbearable but almost any SW person will tell you patience is a virtue. It will save you time, money and grief in the long run
RO units can be expensive but J&L aquatics sells a decent one for relatively cheap which I use and it does fine and you can pick up spare filters for any RO unit at almost any place where bulk water is sold
RO UNIT link
http://www.jlaquatics.com/product/vt...+-+100GPD.html
Good site to visit for most fish and coral needs is liveaquaria its almost the bible for SW hobbyists
http://www.liveaquaria.com/
Hang in there and if your not sure ask questions here first before going to a LFS the knowledge base here is second to none and nobody will try to steer you wrong