How do I go about acquiring such a generic product?
First when a product is "generic" it may not be patented or it's patent is open, meaning that you can make fair use of it. Still you need to check with the patent office or an expert.
In your case you need to search that your idea/invention is not already patented (someone could have the same idea for a product a time ago, patent the product but no further development on the idea or product had been made).
What I understand from your question is that you will be patenting the software and not the wireless device, so you must search for patents on that area, and see how other similar devices are patented (what is protected by the patent, the software or the device ?).
There are patents that after a time the owner don't renew the patent, so you can buy the patent or make use of it.
I will strongly recommend to check this -> http://www.uspto.gov/ and to talk to a patents expert.