Well, all the digital fpv stuff, facing the same thing as rest of industry... need chips to make products. So for now, just to try it out, got 2 analog setups. Always wanted to try a live feed on my rc car, rc mower... Now I can.
One is a micro all in one unit that runs off a 1s 3.3v lipo. Its the camera, Rx, and antenna all in one board. Then I got a bigger camera lens unit, that runs off of a higher voltage range along with the Rx. The Tx unit is composite cables. Luckily I have an older but big screen tv I can hook it to.
These rely on airflow for cooling. Wont be much up on the track. Luckily i have some small cooling fans i can use. Wish i had a dummy engine. For first few setups going to use one of my freight cars. But in one of the links you sent, guy used the pivot point of trucks to mount camera to. Good option to try.
They also make boards that allow you to switch between cameras. But they need a PWM signal to switch. Dont want to run my aircraft radio all day. Has to be a way to make something simple, or find something out there. So I continue to search for that.
Now I sit and wait. Amazon said I would get stuff today, but look this am, and shows delivery tomorrow.