NETGEAR C7000 (Old model)

Good Morning, 

Looking for some direction for wifi coverage throughout my whole home. I have a 1600sqft home with a detached garage in the back. I have the Netgear C7000 Router connected to Spectrum internet installed towards the back of the home. Now because the router is at the back of the house i get good coverage in my garage, however my office and livingroom is at the front of the house where wifi lags. I ran an ethernet cable from the back of the house, underneath the house to my office in the front of the house so my computer can have direct access from the router. It works great. However I dont get great Wifi towards the front. I went ahead and bought Netgear Wifi Mesh Range Extender EX8000 to see if that would work. The internet runs a whole lot better however i find myself turning on/off the wifi on my computer because my computer doesnt grab the wifi when I first use it. Would have turn off and on the wifi in order for my computer to connect the computer. Is there a better extender or another way where I can get good continous wifi coverage in my home with out rebooting my wifi for connectivity??  Below are the two products I have purchased. Need input!! Thank you so much 

Amazon.com: NETGEAR C7000 (Old model): Computers & Accessories

Amazon.com: NETGEAR WiFi Mesh Range Extender EX8000 - Coverage up to 2500 sq.ft. and 50 Devices with AC3000 Tri-Band Wireless Signal Booster & Repeater (Up to 3000 Mbps Speed), Plus Mesh Smart Roaming: Computers & Accessories