trek 3700 hybridize
i picked up a 2009 trek 3700 that has been living outside, leaning on a shed wall for short $. the chrome is flaking off one leg of the suntour fork slider. i am thinking disc brakes for this project, trek states the drop outs are disc compatible and indeed it seems trek makes a disc brake caliper holder for the rear @ around $15. front fork needs to replaced [rigid type] so that is not a problem. should i go 29er or stick with 26 wheels and i am curious about which disc rotor diameter to use, no experience here with disc brakes.
it looks like around $300 for the 3700 project including the cost of the bike. i tried to look at the kona dew plus but no dealer had one in stock and could not provide a promise date for getting one in and a special order is extra shipping. i am out on 1 to 2 hr rides 3-5 days a week, so i don't need the best best stuff just serviceable.