Joined: Aug 2009
Posts: 7,717
Likes: 4,118
From: Berkeley, CA
Bikes: 72 Cilo Pacer, 72 Gitane GT, 72 Peugeot PX10, 73 Speedwell Ti,l, 75 Peugeot PR-10L, 80 Colnago Super, 81 Zinn, 85 ALAN Cross, 85 De Rosa Pro, 86 Look 753, 86 Look KG86, 89 Parkpre Team, 90 Parkpre Team MTB, 90 Merlin
Since this is going to be a working/riding bike, I don't see the point in spending tons of money on NOS parts. What's the rear spacing? 130mm? That may limit the option to use modern MTB groups since Ti should not be respaced/cold-set. Also, I don't believe these frames came with braze-ons for disc brakes.
I vote seeking out a lightly used Deore XT group (ideally from a a donor bike, since it's a buyer's market for used MTBs).