Driveway alarm

Here is a simpler and somewhat cheaper one, that I have not tried yet, but should be good for short simpler setups.  http://amzn.to/2wV84eJ

Speakers

Best Bang for the buck

Wireless Routers

The ultimate

Best Bang for the buck

http://amzn.to/2fzqHxh‚Äč

Personal Cloud NAS

Best Bang for the buck

Printers

Stan The Mac Man

Computer Speakers

http://amzn.to/2xBxQlp   

This is one that I use. You can add up to 3 more sensors for a total of 4. You can also add recievers. I have the walkie talkie one that doubles as an intercom.