Welcome to AVS.
You should be fine with the 1712 and I would definitely spend the extra money on the speakers (RC-10s for $299 are a GREAT start, but don't forget to budget for stands). Do you already own the micros/sub? If not I might recommend starting with a good 2.1 or 3.1 setup with a non-Energy sub that you can eventually build on. Ideally sub choice should be based on room size so maybe look into the used market since you're on a budget. I personally wouldn't skimp on speakers or sub, and think long term if possible-it could save you money on the end. Good luck.
Somebody told me it was frightening how much topsoil we are losing each year, but I told that story around the campfire and nobody got scared.