Hello
I can make that device for you.
As i understand, you need some web-interface to move up and down for specified lenght by one click.
With steppers you don't know precise position of weight when it placed in most low position (spool of rope have big changes of diameter when rope is unwinding, so counting of steps may be not informative).
So, i'd use usual (non-stepper) motor, with sensor of "end-position" for both end of rope.
And, yes, usage of WiFi is most preferrable way to communicate with device. In some way it's even better than Ethernet.
There is no real pros for cable connection: usage of USB will be cheaper, but 15m is enough big distance for USB, and Ethernet will take same amount of time and price.
(You will need just write WiFi credentials to the device, it's easy.)
My price include shipping by regular avia-mail (not DHL express-service), terms not include delivery time.
Have a good day.
Maxim Bulkowsky