In the first instance I would go to a Knobs & Knockers type shop and find a door handle that feels comfortable in your hand and looks the part.
I started going down the online route for door handles and having visited a shop where I could actually feel and use the handle made a massive difference to what I wanted in my head versus what I wanted in my hand.
Once you've found a handle to your liking then you could investigate online procurement or see if your local company will do a discount for bulk purchase.