Ruby on Rails app, add checkout page and configure paypal for payments

Check pls [login to view URL] On a single apartment page, after you choose start_date and end_date and press book now, it should redirect to the checkout page ( with info about order, eg. total, user name etc..). This checkout page should have a button that redirect to paypal to pay for this order. After payment done, it should redirect to the page 'my trips'. Everything should works perfectly. Please note, before bid, make sure you can handle this, THIS IS NOT for junior rails developer or anything like this.