My first reef was a 40g, so Im thinking 34gallons....not that far off, but kinda is when the volume missing is 5.6% of the water volume. I would look for something a little bigger, just to make it easier on yourself, plus then u get more area for coral
. I would say stay away from the little pre-made tank set ups, I just don't like them.
Do a little search, see what other people trying to set up a SW asked, you will find that there is already a ton of information on this board.
Good Luck!