I can't speak for the F2, F3 or FE, but I'd pick the FG over the EM as there is no manual control on the EM - strictly Ap-preferred. And as far as price, I wouldn't pay more than $175 for the FG and then it better be in sweet condition. $220 is high. Check eBay.
As a relic backup, I don't think you can go wrong with any you mentioned, but there's people here more qualified than I to speak on the others.