why would you want to motorize something so beautiful as that? that is a super nice bike.
honestly I don't think any kit will work well with that bike... not without modification that could damage the bike anyways.
my advice would be to find a cheaper craigslist bike closer to the one i pictured earlier. it works universally well with any kit you do decide to buy... you can even try several kits for the price of a ruining a niCe bike like the one you posted.
try looking at this kit... scroll to the bottom of the page.
Golden Eagle Bike Engines, Geared Belt Drive Bicycle Engines / Motors for Mountain Bikes & More
I would rank it between the jackshaft and frictiondrive on almost all points. it is my favorite kit so far and is possibly the best you can buy.