RE: FM receiver
Hey, you can buy a reliable, compact, efficient dual-conversion FM reciever for about $50-$60 these days. That's not even an hour's worth of a *good* electronic tech's time!
These receivers have a high level of integration (custom ICs = small), surface-mount componentry (reliable and small), and a proven track-record of performance. So why mess around using standard components (large, less robust) to build a bulky, potentially unreliable receiver?
You can buy receiver kits from various vendors -- but surprisingly, the prices are often as high if not higher than those charged for built-up units from reputable manufacturers such as HiTec.
Many years ago -- when even the store-bought receivers used regular off-the-shelf components, I did build my own RC gear. This was handy because it allowed me to have one of the world's first transmitters with onboard elevon/flaperon/V-tail mixing, dual rates, etc.
These days it's just not worth it -- all the features I want are available in commercial sets at ridiculously low prices (compared to the value of my time).