no, you don't have to choose hard or soft. but some coral that has a calcium based skeleton (hard) need more PAR for photosysthesis, compared to most soft corals. i would also retro fit whether you went with VHO's or T-5's. if you go with VHO then get the high output bulbs, and a nice ballast like an icecap so that if you ever really get into it and need more light and don't want to go down the road of buy metal halides, you can switch to t-5's with single reflectors and you could fit double the amount of bulbs compared to the VHO's. check out
www.premiumaquatics.com or
www.reefgeek.com for different lighting options and retro fit kits