If you are afraid of children damage, I would recommend you get a down-firing subwoofer. Children can punch holes in exposed cones very easily, and they will be tempted to do so, believe me. Also, I would go with wall mountable bookshelf speakers. In the price range you are looking at, I would turn to Ascend CBM170 bookshelf speakers, Hsu HB-1's, or Infinity Primus p162 speakers, along with their companion center speakers. For a decent down-firing sub, check out the Outlaw Audio LFM-1 EX. You will want a great sub to start with if you are going to be building up. The Hsu STF2 is a great sub for the price, but it certainly has its limits, especially in a large room. The VTF2 would be far more capable. You might want to get a second sub down the road, and it should match the first, so make sure the first is a real keeper. Deep powerful bass can really impress guests, so this is one area it may be worth it to splurge if you do lots of entertaining. Also look into getting the AM40 pinpoint speaker mounts, these are excellent speaker mounts, and one of the very few that can heavier speakers without having to drill holes in the speakers.