This may be of no help at all - but I use MYOB accounting software - which produces invoices, statements and reciepts in pdf format than can be emailed to customers on the database within it...
Have a look at www.kashflow.co.uk - it's free to use for 60 days with no obligations and you'll have a receipt/invoice ready within 5 minutes of registering - it'll also send it by email for you if you like.
At the very least it'll give you an idea of layout and whats' needed.