For all those three items that you mentioned, you should have no problem finding them in KOMTAR (ICT section)/Prangin Mall/ 1st Avenue (for sports shoes). All these malls are linked to one another and are within walking distance from where you'd be staying.

Heard that there are several camera shops along Penang Road as well. Close to Komtar so you can walk there no probs =))

For more options you can also take rapid bus 101, 103, 104, 10  to Gurney Plaza from Komtar bus terminal. Or rapid 304, 102 if you are waiting at the Penang Road Station.

Armenian street is kinda close to KOMTAR so it should be convenient to move around using rapid penang. And plenty of good makan places around as well so I don't see a need to rent a car (Which costs around rm 90-100 per day not including parking fee/petrol..). In case you get tired/lost in the middle of no where, can just use your phone to get an Uber driver to pick you up =))

You can also browse through tripadvisor to see if there is any new attraction that you/your wife would wanna visit yaa. Have fun! 😊