you coudl keep anythign you want in that tank. however, you couldnt keep anything anywhere. youd be limited to keeping higher lighting corals right on top. if you are able, i woudl personaly recomend at least a 250. but a 150 will get you by.
Wow, that will be an aquascaping challenge for sure and I'd love to see the results! I agree, put the softies toward the bottom of the tank, and any high light corals near the top and you should be fine.