It's a relatively easy change to make, but with everything...you'll need to "fix" some of the impacts that lowering the bars will require.
So here are some clubman's that I fit onto my '79 special. I got them out of a salvage yard for $10--and they were straight! I'll be getting clip ons down the road--so this was a perfect solution for my current needs. But since they were "found" I can't say what the pullback or drop is, but they are fairly standard from what I recall (I had a set way back in the 90's on a different bike and they feel about the same)...
(Unfortunately, I don't have pics of how I routed the lines...and I'm not home to take any this week--but if you need them, I can probably get to it this weekend.)
With regard to issues, I had to address the steering stops, as the bars would hit the tank. Note: I did switch my tank for an xs750 which is wider, but I am pretty sure the stock tank would have also not cleared the clubmans. I chose to drill into the stock stops and I tapped them to add a small screw which I can now turn in/out to adjust the stops. Kind of a pain to do...but worked for me.
(With clip ons, you may be able to turn them out a bit so they don't hit your tank and not deal with the steering stops at all...I'm sure someone who has them can voice their experience).
As far as cables, if you're currently using stock (Standard) length cables, they should work...but may be just a tad long, and you will likely want to reroute them so their "bends" aren't too extreme... meaning the throttle cable could be re-routed on the other side of the frame taking up a few inches of length that you gained by lowering your bars with clubmans...same with the clutch cable, etc. The brake lines may also be an issue...
For my bike, I started with a "Special II" and high bars, so I switched everything to "Standard" lengths and that seems to work well enough... I haven't changed the front brake hose though, I simply re-routed it and switched the mounting points so that the bends wouldn't be as extreme...but it's still far from perfect. Ultimately, I'm going to get a braided line and go direct from master cylinder to brake, getting rid of the connection point on the lower triple tree...I just haven't spent the $ on them yet.