For clams you will need to upgrade, I would go with mh for them. For softys I would keep what you got and put them in the middle or closer to the top of the tank, because 29gal tanks are kinda deep and pcs dont penatrate the water very deep, also with pcs you need to replace them ever 10 to 12 months or so otherwise they wont work as well. I have a 30 long with 192 watts of pc's and my corals are doing fine. In the tank I have pom pom xenia, shrooms, ricordia, kenyi trees and psp and there all doing fine under the lights. So if softy is all your going to keep then IMO theres no need to upgrade, however, if you want to keep more than softys I would go metal halide or t-5 s with mh being the best choice.