Good ideas. I've always thought that a city of the size and importance as Berlin SHOULD have a top class football team. And I've never really thought that Hertha fit the part. In recent years we've seen Union Berlin push above their historic level, playing Champions League football and such. So I would certainly enjoy seeing Hertha in a duel with their rivals, however likeable Union actually are as a club. I remember Hertha played a few European games some years ago, playing Brøndby among others, so historically it could also make sense to take them that far.
Tenerife also played Brøndby in the UEFA Cup back in the 1990's, as I recall. However, I would probably find it hard to see them climb to the very top of Spanish football from their location in the Canaries, but you don't tend to continue your stories for that long anyway, so I don't suppose that's a worry in this case. QPR could be a good shout, plenty of London rivalries to dive into, but with the amount of English careers here, over the years (my own included), this idea probably speaks to me the least.
Bordeaux would be a really good shout. They had some really good players a decade ago or so; Gourcuff, Chamakh, Wendel, Plasil, Gouffran, Ciani etc... Reaching the Quarter Final of the Champions League, I really liked that team. But you might want to be fast with this one. With Lyon's current position, I'm really quite taken by the idea of relegating them and taking them back to the top (currently 18th in Ligue 1). So if my (so far) short-lived Sampdoria campaign has scared you away from Serie B, then you might want to start with Bordeaux, before I get too attached to the idea of starting with Lyon 😉