Bus/Coach Seat Booking System with yield adjuster

We require a new build site with the abiity to book seats on our regular coach/bus operations in the UK. Our coaches have between 17 and 49 seats and have multiple stops max. 3 on 1 journey. Trial. The website, will for the start, be a trial system booking seats on 1 coach(per day) going from Leeds - Sheffield - London (then back) - sheffield - Leeds, once per day, 7 days per week.. It will carry 17 passengers. The website interface must be intelligent and use a yield adjuster to make the most of seats available which must allow space to collect passengers from midway collection points (sheffield) and make use of the space between points then onwards, doing this by offering lower rates to encourage people on. Again the yield adjuster should be capable of this automatically. The yeild adjuster will increase fare prices as it reaches close to the departure date and indeed time. The system will be able to accept payments by card and paypal. The system must generate a ticket that can be printed by the customer The system must have an option for the ticket to be text to the customer. This type of system can be found on many intercity coach operators all over the world.