Relying solely on In-Tank equipment limits your options for filtration equipment somewhat. That being said, some of the most outstanding FO, FOWLR and Reef systems use only what can be placed in the tank for filtration.
Under Gravel Filters are the old standby and work quite well. They do require a bit more maintenance than some of the other Biological Filters, but they are inexpensive (you can easily custom build your own UGF) and easy to install. The Undergravel Filter Controversy will probably rage on for years, but you can read the arguments and make your own decision as to whether or not it will work for you.
There are a number of In-Tank-Skimmers which take up little room in your tank and work quite well.
For water circulation in your tank, the wide variety of Submersible Pumps on the market today gives you plenty of choices to pick from.
If you have any questions, the Forums is a good place to post them or to see if someone else had the same question, which has already been answered.