msd distributor choice

I need to get a distributor to go with the MSD6AL. It is for my 340 416 stroker motor. I am running a 750 holley with electric choke. I want the car for mostly street cruising on the highway. Should I get a vacuum advance ready to run MSD distributor or should I get an MSD pro billet distributor without the vacuum advance. MSD said I could bypass the vacuum advance if I wanted to on theirs? My mechanic said to get the vacuum advance to get the best on street driving? Any idea on what I should use for plugs. They have to be the small hex as I have dougs headers and edelbrock aluminum street performers and they need the small hex for the socket to fit?