JoomDonation have a different component called PaymentForm that just (I think) lets you build up an invoice in effect, capture the data and pass it through a payment system. I don't have it installed, but there is a demo here:
joomdonationdemo.com/paymentform/
You may need the EventBooking functions for other things in which case that makes sense, but it doesn't sound like you are using it to manage the diary for the 6 week camp... ...so I thought maybe you didn't need it?
