The camshaft runs in the block. If its fit is sloppy, you have to mill the caps.
I always either got my crank bearings from NAPA, an independent auto parts store, or That tractor parts place in iowa that I can't mention here.
The rear and center main are from an OHV engine bearing kit, same bearings you just have the front main left over. The front bearing is a Bower MA1212EL roller bearing.
The rod bearings are the same as for the 206 OHV engine too.
There is more to this than slapping in new bearings. You need to mike your crank and see which undersize bearing you need. The book says .003 clearance is max. From experience, you will hear knocking if its .002 or more. Your crank may need to be reground to fit in undersize bearings.
You also need to torque the caps to the rods and check the big end bores for being out of round. This is especially important if you can hear the bearings knocking now, the hammering distorts the big end bores and they get eccentric. If they are out of round they will need to be re-sized by a machine shop. Bolting up a rod with new bearings in an out-of-round bore will lock it to the crank. BTDT.