Water movement can be controlled through the use of powerheads and careful design of internal water flow (such as location of filtration system points of inflow and outflow). READ THIS:
I'll agree with Liz on this one - do some mroe reading anf research so you can make the decision that you deem best for you. once thing is for sure, animals, especially SPS need water movement. Much like we need to have a car - BUT, what type of car you buy, for example, interior, radio, color, horse power etc, is dependant on the consumer (you).
I used a good return pump (not over the top with flow) and 2 internal water movement devices (TUNZE and Vortech) on my 180g reef. I had no problem keeping SPS although some hard core SPS keepers would say I didn't have enough flow.
Also, the type of biotope you plan to keep will help determine your max flow needs - is this going to be a Bare Bottom reef? or a shallow or deep sand bed reef? What kind of sps are you keeping? montipora? acropora? seriatopora? all have different flow needs.
Take a look at some of the members tanks in the tank section and see what they are using - this will help you get a sense what you should want to do.
i have the same tank and i use a Tunze 6000 with controller. I have 95% SPS. With the 6000 i get about 30x turnover. I am getting by w/ that much flow but you can never have too much flow w/ SPS. I have a Tunze NanoStream 6045 ordered which will bump me up to about 50x turnover.
You might want to rethink mixing SPS with LPS. Aside from different requirements in lighting and flow there is also chemical warfare to worry about. You have a lot of reading to do.