Lighting question for smaller tank

[urbanhellfire]

I have a 31"L x 12"W x 16"H tank that for the past two months had only had LR and a cuc in it. It has the standard 20 watt t-8 tube in it, and that has worked just fine for the LR but Iam wanting to start adding some corals no hard just soft, mushrooms,polyps.

Iam looking to grow easy to medium care corals. My biggest question right now is what type of lighting to upgrade to? PC,HO,VHO?

PC"s look like I could easily mod my current hood to fit them in, but are they any good?

I have seen that you can get a ballast " ice cap " that
will run HO or VHO lights and that could be good choice for moving up to a VHO tube in the future?

Iam just not sure which way to go with the lighting.

Anyone help a brother out?