Before 2014, I said Canada's best alternative other than F-35 would be actually Su-30 variants (disregarding the logistics and new systems) Russia and Canada geography is very alike, cold and empty.
Now, F-35 is really the only alternative, there is absolutely no point in getting gripens. But our government will dilly dally till CF-188 starts falling from the sky.
Mixed fleet (F-35 - Gripen - Erieye) is arguably the best bang for buck fleet Canada can hope to get. There's simply no point going for other western fighters, nor throwing additional money into air in general, USAF is always going to be dominant.
Additional lightnings don't add nearly as much value as the already contracted ones, and full lightning fleet only made sense in a world which Canada itself proclaimed as gone. I.e. it was in essence paying symbolic feudal homage for a right to be another civilized one man on the right side.
What they caaan do is start producing IADS. In Canadian case, pretty much from scratch, as they have nothing.
Which indeed reinforces American point of free riding.