First off is to preheat your mash tun. If you don't you will be fighting temperature loss throughout the mash. I also add the strike water to the tun at about 5 degrees higher than the target temp. I then let the temp drop to the strike temp before I add the grain. The mash stays at temp much better using this method. The first thing I learned doing all grain is that it is easier to lower the mash temp than it is trying to raise it.
You are using 10 pounds of grain so as a minimum use 1 quart per pound for the mash (2 1/2 gallons). Some folks like to use more than that but I have pretty good luck at this rate. The sparge will be 1/2 gallon per pound of grain and I like to add a bit extra just in case I don't extract all the sugars (5 gallons plus add a gallon just in case). The grain absorbs approximately .1 gallons per pound of grain so about 1 gallon will be absorbed.
You will be alright using 170 degree sparge water but you might think about adding some 180 degree water to bring your mash to as close to 170 degrees as possible for the mash out. This will stop the conversion process. Either way I think you will make good beer.
What method are you going to use for the sparge? My advice is based on fly sparging. Batch spargers will want to chime in as well.