The Su-34 is the appropriate aircraft for this role...
...but there's 0% chance of the PAF getting it.
We should focus on how to tailor actual projects in the pipeline (JF-17B, Block-III and AZM) for strategic roles.
So, for example, the Ra'ad II looks like it was optimized for the JF-17. The design (especially stabilizers) seem compact enough so that it could fit under the wings. It also has a range of 600 km, which means the JF-17 can deploy it from within our borders (and offset the range loss from swapping out the fuel tanks).
The Block-III and JF-17B should both fare better in terms of range thanks to having increased internal fuel capacity and in-flight refueling capability. If anything, the PAF should acquire enough of these aircraft (...maybe an upgraded JF-17B variant with AESA radar etc) for the strategic strike role (using Ra'ad II).
It isn't ideal, but it's the most realistic way of making it work. For the long-term, the PAF's focus would be on AZM.
Let's see what approach they take. It'll be larger than the JF-17 for sure, but it might be smaller than the TF-X (it seems Turkey will use a GE F110-class engine?
@cabatli_53 ). Still, it'll likely retain the ability to carry the Ra'ad II or some ALCM of the future. If Turkey succeeds in securing a non-ITAR engine, the larger TF-X (which the PAF did show interest in) could also factor in as a strike option, especially if it has a larger internal bay.
That said, for strategic strike -- and deep-strike, SEAD/DEAD, etc -- the PAF could be better of studying the utility of drones. It costs a lot of money to set-up design and testing infrastructure for AZM, why not extend its use to design a drone with a 3,000+ kg internal payload? You can load a UAV with warheads and send it on its merry way on one-way trips to targets, no care for loss or risk. You can re-use inputs from AZM (i.e., engine).