The logical approach would be to ditch the tits then make up your mind about reconstruction later--particularly if you are in two minds about what you want to do. Unfortunately, it's a bit more complex than that.
First hurdle is finding out if you need to have chemo before surgery, which seems to be pretty common if you choose reconstruction s or have certain types/grades of cancer
If you have private health and time to tinker around, take leave etc, you have quite a few options regarding surgery and reco. If you are relying on the public system, anecdotally, delaying reconstruction can see you languishing on waiting lists for years to get your new boobs finished off, depending on where you live or where you are willing to travel.