Best is a Gen
2nd Best is the Kbiz Franken Ulti 088
3rd best is the ulti 088
Get an Ultimate. i had mine lumed by Vac to OEM specs and it is just amazing. Needs the OEM Crown, tube and CG mod to put it in KBiz's shadow but the Ultimate 088 is the way to go.
KBiz and I have both had issues with the Davidson crystals. Not sure if it is true for all of his crystals but Davidson uses a sapphire -plastic sammich crystal for his automatics. Not only is the font way off but you can not have them AR treated is it is a severe pain in the ass to do so. The Ultimate crystal (and according to Kbiz the new Ulti 088 specifically) is the best aftermarket Panerai crystal ever made, better than the $150 wholesalejewelers crystal on ebay.
In any event, good luck and have some fun with it.