Can you care for its dormant season? I am just involved with a trade of 2 plants purchased earlier this year than cannot handle to PNW climate at all in the winter. These were winter growing Pelargoniums, how silly of me. For cactophiles can you provide the cold and light necessary for blooming? Which is why I moved to Epiphylliums, Rhipsalis Schlumbergia, and some other cauduciforms that can stand no or little light and moderate cold for a bloom. Not to say that I could not grow other cacti, its just jungle cacti I am caught by.
A good place to start is Birhmann's Caudex, Water, Temperature and Light: http://www.bihrmann.com/caudiciforms/div/vstt.asp. It will save you some heart break. And maybe give you a broken back! I have several plants that need a fork lift to move inside to out. In the scheme of things, I am a small timer. But research your plants well, and buy from a good distributor.
Arid Lands is great, Geraniaceae http://geraniaceae.com is great, and I personally like Mesa Garden http://www.mesagarden.com/ but that is a mixed bag. Geraniaceae, is pay after delivery, And Arid Lands is beyond belief in producing high quality plants. One other store worth mentioning, that I have bought directly, and is one of the Kings of Caucidiforms is the Great Petaluma Desert http://www.gpdesert.com, he is a great source of info.
Do not dispair if lighting is a problem in the winter, a new greehouse, light table, or halide system can make you very very happy. Its just this unemployed guy is not in the state to have one yet.