The bottom bracket in this Lotus Odyssey has too much play in the spindle, and I'm sure the needle bearings need to be replaced. I'd like to install a modern cartridge type while I attempt to find and replace the needle bearings in the original. The crank is Sugino triple Mighty Tour and it's shifting thru all 6 cogs of a Suntour NW Ultra very nicely at this point even with the play in the crank.

Given the measurements my questions are; Should I get a UN55 in a 118 (use DS shim) or 122.5? (not sure if there's offset to these), Is there another BB choice I should consider? (not afraid to spend more money within reason), How do I go about replacing the needle bearings? Do I need special tools, Do I take the cups to a shop? I'm pretty handle and have home work shop, and where can I order them from?