Jeff, as you are young and probably be mostly city riding, with touring as time allows, an 8/9/10 speed cassette, low of 32 should be fine. With a 26 upfront, that's give you a granny for up to 16% grades with 35 pounds of gear aboard. I'd need the 36, but I'm old. There'll be times when you'll wish for a higher upper end, but probably not too often. Get a 14 pound road bike for speed.

As for tires, the choices seem nearly limitless. I ride on Maxxis Overdrives as a good compromise, cost vs weight vs puncture protection vs liveliness. Schwable is the gold standard. Vittoria Randonneurs get very good reviews. All from a touring angle, not necessarily city riding where most want as much liveliness and puncture resistance as they can get. Liveliness usually translates to light.

As for the wheels, I'd say keep it under 215 pounds, that's you and the gear. Most new tourist pack way too much. Go to www.crazyguyonabike.com for all there is to know about touring. Check out this link.

As for saddles, many swear by the venerable Brooks B-17, a leather saddle that must be broken in. I ride a recumbent now mostly because I could never find a saddle that respected my rear, including the B-17. Good luck with the saddle issue.