Wordpress, booking plugin - repost

Hi, I'm looking for a Wordpress plugin for a simple booking system, with [login to view URL] as reference (click on "KURSUTBUD" in the menu to display their booking page). Pretty much want an identical frontend solution with the same look 'n' feel and functionality as well as easy management in the admin section of WordPress. A rough admin section specification: - Have to be able to add, remove and change courses. - Have to be able to add, remove and change course information and categories (like price, category, course dates etcetera). - Have to be able to administer number of course seats available and between statuses "open", "a few places left," and "closed"/"full" (displayed with icons). - Have to be able to remove a "closed"/"full" course manually and change course statuses (hide/show them in frontend). - All courses must be displayed in backend, regardless of status (but not if deleted). - Have to be able to manage bookings made by customer (add, change, delete or move bookings to another date). - Have to be able to change the amount of visible courses on the frontend booking page. - Have to be able to link for further information on courses. - Have to be able to administer (add/delete information and customers) retrieved customer data from forms. Different from [login to view URL]: - Wish for a bonus code field where customers can type in their bonus code for x % off sale. - Wish for an automated function generating an editable standard invoice in backend with the customers details from the frontend form. And when being able to send it to customer's email from backend. I know there already are a great variety of booking systems, sales systems and equivalent plugins out there (like Gravity Forms), but didn't find the one for me. If possible, welcome with an estimate cost for this plugin project. Looking forward, Crosslateral