There are alot of variables to consider when talking about lighting. One is the turbidity of the water, another is the spectrum of the bulb.
The turbidity can change because of the substrate you have, the skimmer you use, weather or not you have ozone bioload,
filter floss, the amount of water flow you have, ETC...
While it is possible to keep SPS under any type of lighting system the bottom line is how much of the right type of light reaches the algae in the corals.
As for the skimmer, if you can, build a geoff skimmer it will work great on a 29 gallon tank and be cheaper than buying one that may not work nearly as well.
The size of pump you plan on using is going to be affected by the size of the skimmer you use. I personally don't want any water being sent back to my tank that has not been processed by the skimmer. Remember that the return pump should not be considered the only source of flow in your tank. It will need to be suplemented by either power heads or a CLS of some sort.
The largest issue I see with your plans is that your tank is very small and you want it to be dominated by softies, they use chemicals to kill
SPS corals and in a tank that small there will be very little room for dilusion of the chemicals and it will make it exceedingly difficult to grow your SPS or even keep them alive. If you want to have SPS and softies get only a 2 or 3 small softies and the rest SPS and run alot of carbon and be sure all the water leaving the tank to the sump runs through the carbon and be sure you replace it regularly.