I've owned literally dozens of Midway cocktails, so here's my 2 cents to consider.
Whenever possible, I try to keep the original glass; unless there are scratches or the art is totally trashed. You can backpaint it and the glass makes matching somewhat less critical and in the black areas of the art, you can't even tell.
I'd start by going that route and see how you like the results before shelling out the funds for a new underlay + a new clear glass top.
Also be advised that not all underlays are created equal and there are some that have Pacman artwork, but are actually trimmed as a Ms Pac, as if whoever made the art only had that one die style to cut it. At least verify that the Pacman underlay you're buying is in fact trimmed differently than whatever Ms Pac they sell, if they're exactly the same, then the Pac won't look right around the control panel.
Finally, for glass I've always had great results with AMDG Amusements. They sell an excellent cocktail glass that is tempered with no logo and has the correct highly polished edges. Best of all it's relatively cheap and always comes well packed.