+1 with what Bouschie said, on the razors. The brushes found at CVS, Rite-aid, Wal Greens, Walmart, are usually the Van Der Hagen Boar brushes, some may carry the tweezerman. The VDH boar brushes seem to hold up well. Have you thought about having your Grandpa's brush restored? One of the vendors here could probably do it (look under the classifieds).

I would think twice before using your Fathers sharpening stones...Unless you know what grit they are. Typical setup might be for a full set of stones is a 1k (setting bevels) 4k, 8k, and a 12k - if you plan on honing your own razors. I'll point out that you don't need a full set of hones if your going to buy shave ready razors that will only need maintained (edge).

At the very least you need a straight razor, shave brush, and shave soap or cream (I reccomend Real shaving cream or RS starting out). If you want to maintain your edge I would settle for a 12k hone or if you can find a decent vintage Barbers hone (you might use it every 6 shaves YMMV) I think I use mine twice a year but I have 12 straight's razors in my rotation. Read the Wiki on here, lots of info.