I would wait for the PCs. Aclimation is a sensitive time for corals, so you will want adaquate lighting before you start introducing medium to high light specimens.
How many watts of PC lighting are you getting? Most people would recommend 5-6 watts per gal minimum for raising corals. However, there are people who report using less with sucess.
The powerhead issue may not be an issue at all. Do you know approx. how many gallons per hour your filter system turns? For a 10 gal tank, I think the recommended flow would be appx 100 gph. However, this depends on the types of corals you plan to introduce into the tank.
http://www.liveaquaria.com/ gives good general info on these types of requirements for specific corals.
Good luck,
AEB