are you looking for something to fill that entire space? With the plumbing right there, if it was me I would get some sort of standard 6ft tank and put in a sink next to the tank with maybe a water station or something to do auto water changes.
Hello I'm from www.billgoody.com and we're currently full but I would also suggest reefiness' option. Try to plan for the long term. Most people think the cost of an aquarium is the fish tank but that's far from the case. If you'd like feel free to call me on my cell at 718-440-onethree2one.