daily tour booking

we need a simple online booking system for a local daily tour operator basically it own 2 Bus , 2 row model (like london bus): 49 seats on first row, 20 on low row ( each bus) so total for each bus is 69 seats we need to put online the ability for customers and/or partners to reserve (booking) themselve the seats, and when on single day seat (on each bus) reach 69 .....it doesn' accept anymore best way is to have the ability to creatre as many "bus" we need and modify the "seats2 parameter: this for eventually future necessities.... need also a simple registration for customer/partners who want make book with these fields Company Full name email telephone type (drop menu "Customer" "Partners")