Ideas to add onto current business

I have acquired an investor and have 60% ownership of the company. I have the funding, and nearly every aspect of the business figured out. We have a month or less until we open. My investor purchased the building. It is currently being remodeled, updated, and signage is going up. I am starting an electronics repair business. It will be a full-service repair store (we will fix cell phones, tablets, computers, TV's, game consoles, etc).

I have around 1100 Sq feet of usable space and only around half of that I need for the repair side. That includes area for buying, selling electronics and refurbishing devices. Also a wall-rack for accessories.

What other business/niche could I put into the store that would be interesting, in-demand, and profitable if incorporated in the right way. I have some ideas but nothing has really hit me like "wow that would be awesome".

Thanks!