If you're expecting people to pay online then you need an ecommerce solution not just a website.
I'd go to someone who's done this before and can offer the whole service off the shelf. It needen't cost loads (although clearly it's more than doign it yourself) but for payments you need soemthign secure that has a link to proper payment gateway/acquirer.
He already said he doesn't need an ecommerce solution, just a means of accepting payments. Google, Paypal and a dozen others can provide this with buttons and security just by pasting in a few lines of HTML generated in a wizard in your account.
For a professional look take a cue from something off Template Monster and mirror it.
The trick for beginners is to design it completely offline e.g. in word if your are comfortable with that. Then build it with a web design program. Rather than doing both at the same time.