The MLCS bits are on the low end of the quality scale so you may want to go with a better brand if you have a few windows to do. You may need to size the bit to match what you have. I'm not sure how many options there are. For small bevels I would use a router. There are a lot of different angles available. For large ones, as in the main sill I usually do those on a table saw with the blade beveled. You can do the small ones that way too but there is more sanding involved.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.