a bit of advice please

I am looking into purchasing a new studio kit. I know this has been covered a million times, but I have done searches on previous threads and have not found the answer to my questions. I have a D90 and a SB-900. I am looking at getting this setup:

http://www.bhphotovideo.com/c/product/541987-REG/Westcott_240P_Strobelite_Two_Monolight_Kit.html#specifications

With the equipment I have what else would I need to make it all work? Also is this a decent setup for someone not using it professionaly, but would like to move into that area at one time? I am mostly looking to use it to do portraits of my family and my newborn son. Also can anyone recommend a good backdrop, stand, etc?

Thank you for your time and help,

Bill