I like to use quartersawn spruce for the soundboards(guitar tonewood will make many), Mahogany or another light hardwood can also be used but it will need to be thinner, just under 2mm.
In this video I use Forstner bits and a bench drill to acurately make the recess for the inlay, please note you cannot do this if you don't have a bench drill( the bench drill is the main power tool for this instrument - I use it to do the rosette, thickness the sides, and install frets too) The inner diameter is 28mm but in the video I refer to a 32mm size for the rosette, in actual fact I ended up using a 35mm one as the purfling I used added up to 3.5mm wide, you can use wood veneers to match the size of bits you have or you can purchase forstner bits to fit the size of purfling!
I normally use an mdf board the same shape as the soundboard to do the gluing up of the braces, I couldn't find it today so It meant I had to use my long reach clamps!! improvising is part of the making process...
You can taper the ends of the struts after gluing. but with the softwood soundboard at around 2mm I go for the safer option.