(This type of thread can get more long winded than you may want, but of course you want opinions and personal experiences with the equipment discussed to make your decision)
I would 100% recommend getting the Dillon dies and Dillon powder measure. Previous posters have metentioned the more obvious differences between Dillon dies and Lee dies but it does not stop there. It's the entire reloading phylosphy of the two manufactures of reloading equipment. The dies reflect this. The Dillon dies can be taken apart for cleaning and not lose the settings. The Dillon dies set will have a separate seater die and another die for crimping. The Dillon die will seat the bullet "absolutely straight" and not buckle/bend the case. I have found the Lee combination seater/crimp die will sometimes fail to do this and buckle the case. This leads to the Lee factory crimp die.There is no need for the lee factory crimp die if your Dillon 550b seater die and Dillon crimp die produces perfect ammo. The Lee powder measure is not what you want for a 550b either. Do your self a favor and get all Dillon stuff. Your Dillon NO BS warranty will be 100 percent for the life of the press.
With the above said, the Lee standard sizing die and undersized sizing die can be used to remove the glock bludge in the 40 or 45 cases.
There's gonna be a lot of slow singin'
and flower bringin'
if my burglar alarm starts ringin'