To my knowledge there is no "ultimate" PO 42mm. If you want an ultimate you have two options:
1.) Bump up to the 45.5mm version - available thru all our dealers.
or
2.) Get your hands on a 4th gen 42mm PO and with a few upgrades (dial, hands, pearl, and AR, see here) it will be very close to the gen. The only problem is that the supply of the 42mm seems to have dried up.
I have 2 4th gen 42mm PO. I will be selling one soon so you can PM if interested. It is a Swiss ETA, black bezel, white #'s, the only thing is you will need to get a replacement pearl as the original one has been lost
Cheers!