I started my first sw tank with a 29g regular ole tank and it did really really well. I think that is the perfect size to start with.
The most important things have been mentioned already, but here's a small recap.
Hang on back filter- I used an aquaclear 50, but a 70 will be fine too
2 powerheads, the koralia 425's are a good choice
a good light. As mentioned, the ebay led panels are a great light, they will grow anything and are about $110
Refractometer to test the salt level, or sailinity (much more accurate and about $25)
I'd guess about 25020lbs of sand. Doesnt have to be the expensive "live" sand either
About 1 to 1.5 or even 2.0 lbs of rock per gallon. Doesnt have to be live rock, dead "base" rock is fine. So if you get 35 lbs of base rock, you can get say 5lbs of the expensive live rock and it will move the cycle a little faster
Thermometer- lol small, but important
and either get your ro/di water from your fish store or invest in a unit. They start at about $100 or so or pay the 50 cents average at your fish store for each gallon
You can start with regular instant ocean salt or with the reef crystals, whichever you prefer until you have corals, then the reef crystals are the way to go as it has extra elements that corals will need to do well
I think I summarized what the others said, lol, but this is a basic list.
And for that size tank, you really dont "need" a protein skimmer, as long as you do your water changes.