Apologies in advance if I sound negative as it isn't meant to be - but the live rock and the live sand are not just for decoration - they are a very integral part of the setup. You can start with standard and cycle it if you're a patient soul. It would help more if we knew what you have for a filter, etc. Would this be your first saltwater tank? If so - read on; if not, just ignore everything beyond this point because you already know.
If you want fish that you spend your hard-earned $ on to thrive - or live (and marine fish are not cheap, they can be quite an investment), you're might be better off getting things for your system together as you can and waiting to set it all up until you have everything you need, or saving up the $ to do it all at once. If you're looking for an inexpensive hobby, marine aquarium keeping may not be what you're looking for... Everything costs $ - the RO/DI setup, salt, test kits, chemicals and everything else that it takes to maintain it. Reef aquariums are even more expensive. I just want you to know it can be expensive before you get into it. If you ask the folks on the forum how expensive things are, I think you'd be surprised.
Plus - this hobby is so gd addictive that it borders on the ridiculous... Every weekend I get ready to go shopping and hubby asks, "Going to the crack store?" That's what he calls the LFS.