If building a quad from scratch, you need to start with your frame and then build up from there. The options for the frame include the QAV250 available here, or other 250mm frame design options such as the Zmr-250 and Blackout Mini-H quad.
I recommend the Lumenier QAV250 for a first time build. It is a great design made from quality materials. It has a solid bottom plate and a good antenna mounting location.
We sell the QAV250 on our site, as a ready to fly option as well as a kit.
so, Frame, motors, escs, camera, propellers, flight controller, video transmitter, radio, radio receiver, filter, battery, and antenna are all things that must be considered for an FPV Quadcopter build.
there are many products out there that are available for a FPV quadcopter build. I recommend a RTF QAV250 from QuadQuestions.com with a Taranis X9D radio, fatshark attitude goggles, Sony Superhad camera, and Fatshark 250MW video transmitter.