The real deal. Cost a lot--too much. But I wanted one for more than a decade, and bought some nice but less then ideal bikes for almost as much but was not satisfied.
Bob Jackson custom Special Tourist purchased on local craiglist for under $1000. Close to Riv in a lot of ways.
Lotus Eclair. Traded for it with a bike I paid $100 for--so let's say I got it for $100. Very Riv-ish/Bobish. Suppose I could add barcons. Fine as is.
Recent purchase. The geometry of this bike is pretty close to the Riv. (72/71). I suppose I could add a Brooks as well as drop bars or mustache bars and barcons to make it closer to a Riv--but functionally it's scary close: steel, relaxed geometry, handles wide tires, low gears, and handlebars higher than saddle. Less than $100. Yikes!
So you need to ask yourself--what is it about a Riv that you want? The vibe? The function? Or something else?