The key factor is throat length.
The 12 inch figure above is minimal.
It means that it can drill into the middle of 12 inch object.
A bowling ball has a diameter of 9inches. Therefore since a 12 inch throat drill press is really 6 inches from throat to center of drill bit you have 1.5 inches to play with.
Also are you going to put on table then you are ok.
I use a 17 inch throat drill press. Also with 4 5/8 inch spindle travel.
That is very important too. Remember thumbs are drilled to 2 3/4 depth.
The 4 5/8 travel is allows one to remove drill bits without taking the ball out of the jig.
If you don't want to pay and arm and a leg for specialty bowling stuff.
Do what I did. I got a drill press delivered to my house from
www.deltawoodworking.com. Great delta drill press. described above.
Got a jig off this site used. and also got the drill bits off this site used.
Good luck.
REgards,
Luckylefty
PS sometimes ebay will have good drill presses or jigs for sale.