The snap ins aren't that big of a deal, if you have a 18mm hole, they are pretty snug, and some hot glue will keep them in place.
The PDP sticks use Happ Comps. But the arcades used Wico 360x. Happ bought the rights to that and sell the Happs Perfect 360, which is not identical, but pretty much the same. They use optical switches instead of mechanical ones. If you play a MK arcade machine, you will notice that there is no sound from the joystick due to the optical stick.
A lot of people like the happ comps for fighters. IL sticks are the same design as Happs sticks, more or less. A lot are moving towards the IL parts because they like the components better.
So if you want to replicate the old arcade feel, get some perfect 360 joys and happs or IL competition buttons.
If you want to go with what most of the crowd is doing, get IL sticks and buttons.
That being said, there are a ton of joystick options. I personally have converted to ball tops. Used to be a solely bat top kind of guy, but after playing a lot with ball top joys, I think I prefer them now.
Hope that helps.