Q1 - Do you already have a receiver?
Q2 - Are you going to use a computer or a stand alone audio/video player?
Q3 - What's your limit?
Note that if ceiling mount speakers system is not properly insulated/isolated... it can't be played loud, otherwise vibration will occur and ruin your sound listening. Therefore you're system built will be limited to what your ceiling speakers is capable, unless you'll scrap that later.
Link below might gives you better idea of what you might consider. If you need to upgrade your selection then you might want to cancel your ceiling speakers on your build.