Faintail, for me spraying a plot with gly than tilling it under doesn't do much, since you will be disturbing the soil and releasing dormant seed. If you plan on doing a no plow or drilling in seed than spraying is the way to go.
For your clover, you should have frost seeded some white clover the end of February however it's going to be warm during the day and under 30 at night so get the clover in now.