Mike, I don't want to answer for Geoff but thought I should throw this out there for you. If you contact Bestop customer service they can send you a small parts bag that will include those screws.
Or here is another option: when installing my Supertop I had one bolt head break off. I contacted them and they couldn't just send the single bolt and instead sent the whole small parts bag. If you can identify which screw type it was to secure the header (I don't have my instructions and just remember that it was a lot of them) I'd be happy to send you a handful to hopefully cover any that you might strip out. PM me if you want to take me up on it.
CURRENT - 2012 2-door Rubicon, Rock Krawler 2.5 Max Travel, ATX 181 with 35" Nitto Trail Grapplers
DECEASED - 2008 2-door