I've not fished the Dove, but would imagine the gear you have is more than up to the job for Chub and Barbel.
The Sow is a tiny little river (but great fun to fish
). However, my gut feeling is that your tackle would do the job, but you may feel a little overgunned for the fish and size of river. I've fished it with a 1.25Ib avon rod, going down to about 3Ib line on the float and that felt about right, but I would happily have fished with a lighter float rod (lighter hooklengths would be good, but there is plenty of weed in the Sow to contend with).
The Sow stretch is interesting and a stealthy roving approach is the way to go. Keep low, keep quiet and make use of whatever cover you can find. Oh, and take a pair of polaroids - the water can be quite clear.
There are a few bigger pools on the Sow (including the weir pool at the U/S end of the stretch) that may accomodate a more static approach.
Plenty of time for you to refine your tackle and approach before the start of the river season though. Good luck!
Mike.