There's no need to run separate conduit for the 110 and 220V circuits, they can share the same conduit, just by running additional wires in it. The electrical code has tables for how many wires can run in a single conduit of a particular size, so you or your electrician should check that to figure out what size the conduit needs to be. Otherwise your plan looks good. Like Jerry said, go with bigger conduit and conductors. PVC conduit and boxes are pretty cheap and pretty easy to install. Just takes a PVC cutter (like a shear), a knife to chamfer the cut ends and a can of glue. There's also a limit on the number of bends (3 90's IIRC) you're allowed to pull wire around, so be sure you have pull boxes in the right places.
If I use a single conduit, then I might design it like
See Option #2.It makes sense.
