bubba
with the money you have, start out for your deam
buy a tank not settle for a small one (unless thats what you want...)
do some work save the allowance whaterver you need to do and then buy the next peice and then the next and so one. no you dont need the biggest and best setup in the world
but you are going to put 300+ into a smal tank that IMO is going to be to hard for you to care for in the long run.
IMO go buy that 55 gallon at you LFS leave it empty, save some more money (got a birthday comming up? etc.....)
whenyou got more saved..... well now im just repeating you get it . piece it together one step at a time. all the time reading and researching to decide what the next step is.
or if you must have somethign immediatly than read the daily paper bound eventually be a nice size salt tank come up in the classsifieds