I'd personally go for Taufeeq Umar. He's been doing a decent job.
As far as Jamshed is concerned, I think he shouldn't play tests at the moment. His performances have really gone down of late. His place is questionable even in the T20 side, let alone tests. Should only play ODIs for now, IMO (if he fails in the T20s against Zimbabwe). A lot of people say he is a FTB, and I pretty much agree with that. He was decent in the Champions Trophy, but against WI, SA, and even against teams like Ireland he failed to make an impact. So far, he's smashed India and Australia on flat pitches in India, Bangladesh, and the UAE.
Not only is Jamshed's form a worry, but the eay he defends too many balls and then throws his wicket away is not pretty to see (like he did in WI and SA). was playing good in 1/4 of the test innings against SA, but got out in an ugly fashion.
So, I'd have picked Taufeeq. What about you?