Worry about the cranks later. You don't even have to take a chainring off, just get her working with what you've got. New wheels. If you need a longer reach front brake, get one. Just one step at a time ... unless you have the time and energy to do it all in one hit. It is, however, a bit silly to skimp on the wheelset and brakes, just to save money to buy a crankset you don't need just yet. It's different if the current crankset needs replacing 'now' but if it's working or only needs regreasing, it's not on the 'change it now' list.