Hi Reedreef,
I usually get mine from the buy and sell section on this forum or the sponsors here. I used to get them from cartimar but i have had an inconvenient experience with aiptasia. Nothing against Carti, they do have great livestock at times as long as you know how to check for parasites/pests...As for care, I am no expert by any means but would say its hard to generalize care for softies or any 'group' of corals, there is a LOT and you have to read up on the ones you like - to see if you are willing to spend time and money to support them. Here is a good start:
http://www.liveaquaria.comI think they have Soft, LPS, SPS sections and have very clear and concise explanation of requirements.
I dont know where to get HO T5's, maybe the others can help. If I may suggest, I think LEDs are cheaper to operate in the long run and I personally have had success with a good brand...though the initial spend will probably be more expensive than your tank...hehe.
Whether you go Bulb or LEDs, here is a link you may find helpful (long read but worth it):
http://www.americanaquariumproducts.com ... hting.htmlHTH