I own a Wallyscope and it is certainly a cut above whatever you are going to find on the net. The problem is positioning and focusing the scope in a horizontal position. With a regular USB scope it will take a lot of cleverness. The Wallyscope stage makes it much easier and it has much higher magnification so you can evaluate stylus wear.
Modern cartridges are very well made. I highly suggest the WallyReference tool. It will line up most cartridges perfectly.