A custom cue should hit much better then the butt (you have) and the aftermarket shaft you are thinking of buying on the assumption the shaft will solve a few concerns of yours. Reason I say this is with a custom cue, you should have some say in the making of the cue. That is, if you are going to truly get a custom cue made to your specs. If you have a Viking that you love the hit of, you can mention this to the builder and they should be able to build you a cue with similiar characteristics. This route won't be cheap, but should get you a cue your heart desires.
If you don't go this route and stick with getting an aftermarket shaft. I would try and find someone local with a similiar shaft (correct threading of course) and see if they will let you hit with it, with your stick. Aftermarket shafts are not cheap and for the money you spent on the original cue and now an aftermarket shaft, you are probably close to $300 and could get a solid player in that area. Also, if you do get the aftermarket shaft, hopefully it is a common size threading so if you get another cue made or buy another cue, it will have the same threading thus extending the use of the shaft.
Buying a cue on looks alone could get you fooled when it comes to playing comfort.
ez
If you don't go this route and stick with getting an aftermarket shaft. I would try and find someone local with a similiar shaft (correct threading of course) and see if they will let you hit with it, with your stick. Aftermarket shafts are not cheap and for the money you spent on the original cue and now an aftermarket shaft, you are probably close to $300 and could get a solid player in that area. Also, if you do get the aftermarket shaft, hopefully it is a common size threading so if you get another cue made or buy another cue, it will have the same threading thus extending the use of the shaft.
Buying a cue on looks alone could get you fooled when it comes to playing comfort.
ez