Hi Nick,
I replaced the mechanical seal and bearings on my water pump.I could not find one with the proper cup but unless you destroyed yours you can reuse it and just replace the actual seal.It is a .5" mechanical seal.This should fit using your cup McMaster 9281K144 or you can try this one 9281K84 but I'm not sure the cup would fit and I feel they have made a mistake on the working length.Maybe call them and tell them what you need.
I don't remember offhand the bearing numbers but they are dime a dozen sealed bearings.
Pry the seat out with a pick or small screwdriver,working your way around,it wont break.
If you do come up with a part with fitting cup please do post part number and source.
http://www.mcmaster.com/#mechanical-seals/=krosws go to pump shaft seals
Unfortunately I either did not measure,or forgot to record the seat depth but these are a few of the measurements I got.
I have lots of photos of all the parts with measurements if you need them(minus seat depth).
Seat bore 1"
shaft .5"
cup bore 1.176''
cup diameter 1.182''