I have a '93 Santana Visa that had a 7 speed (28 tooth) freewheel and 140mm spacing, so I had a bit more work to do to go 9 speed. I cold-set my dropouts to 145mm, built new wheels with a Shimano 9 speed hub, found a taken-off set of 9 speed ($50) barcons, mounted an 11-32 cassette and a new chain, and it was ready to go. Everything else, including the old derailleur remained. The bike shifted perfectly front and back. I have since gone to a Mega XT derailleur and a 12-34 cassette. I traded off the 11 tooth cog, which I don't miss and the gaps are manageable. The effort was well worth it. If I had your bike and hubs, I wouldn't hesitate to convert...it is a simple and inexpensive plug and play conversion! And, in my opinion, 9 speed components are much more readily available, at least for now.