I'd strongly consider a Rondo for Smith trade, slightly no brainer to me, particularly if on the win now camp without sacrificing the future that much.
Whatever Smith is comanding contract wise, won't be bad if you plan on competing for the next few years anyways, and still over the cap. Then you'll have Smith, Green, Lee, and Sullinger on your roster with plenty of cap room... not that bad of a place to being the next facet of our journey, and by then Smith's contract won't be a long one.