You are thinking of "scottyintex" - and yes, he did have an R65 sidecar rig, though I believe he traded it for an R90/6 based rig. An R65 rig will work OK, provided that you used a lighter sidecar, like a Velorex, Texas Ranger, or maybe a Cozy (though the Cozy needs structural improvements) and kept in mind that you'll likely be limited to around 65-70MPH top speed with it - better for secondary roads, etc than superslabs.
After I get my R100/7 road worthy again I am going to resume my project of attaching a Sputnik sidecar to it using the Dauntless Motors (DMC) subframe kits, and will keep my R65LS as the 2-wheeled Sunday rider.