Attic Insulation Advice

Hi,
Looking for some suggestions with my house.

I have a small bungalow that currently needs some attention in the attic. The insulation up there consists of paper backed R20 batts that have seen better days. Ceilings are all drywall.
(Also I'm from Ontario so I believe code is R49 because it gets cold!!)

I have been thinking about pulling all the old insulation out, spray foaming a 1" layer down on top of the drywall (due to lack of real vapour barrier) and then blowing in a bunch of insulation to get R50+

Lately I have been thinking about just buying a few cans of spray foam and sealing over any of the ceiling electrical boxes to stop air movement and then blowing in insulation on top of the batts to get R50+. This will save me considerable work and money as spray foam in this area is very expensive.

Any thoughts?