Hi Wildfire - you need a set of metric sockets and a few metric wrenches to get the job done, and I made the cam holder tool with 2 pieces of scrap metal ( 1.5 inch flat strap by about 24 inches long and one ~ 8 inch long piece of 1 inch L shape metal - both at Home Depot cheap - drilled holes at the bottom, bolted in 2 6mm x ~ 1 inch bolts with nuts, then attached the L anbd Strap together with a 5/16ths nut and bolt I had laying around - basically a homemade spanner,. I'll take a pic and post it so you can see what it looks like.
Used the spanner to hold the cam, broke both cam sprocket bolts loose easily.
You can get a pretty affordable set of tools at Advance Auto or Sears -all you need are metrics, there are no SAE bolts/nuts on these things... if it were me, I'd get a 1/4 inch drive and a 3/8ths drive set of sockets, bot short and deep to handle the various studs on the exhaust, intake and valve covers - a breaker bar helps too.
I found that a body sanding block (rubber, Oreillys or Advance, made by Bondo) and a piece of red scotchbrite along with some acetone cleaned the block up nicely.
To specifically answer your question, I have been using 8, 10, 12, 13, and 15 mm sockets and wrenches to pull this thing down - I'll check tonight to see if I used any larger ones and get back to you.
Good luck - it really goes pretty easily, just watch the details.