if you go down the Hawthorne route you can buy x-overs if required and a basic baffle ready cut, and you'll get all the support you'll need. It'll be just a case of glueing and screwing. If you want to copy a design or make your own there's usually someone at a timber merchants who will gladly cut your wood for cash. For my first baffles I used 3/4" ply - the sheet of timber cost something like £60 and the guy who worked in the timber department cut it up for £20, and that included cutting out the awkward elliptical shapes with a jig. If I need to make tweaks, etc I'll borrow my mates circular saw.