Hi Nick
That's very helpful information, thank you very much. I feel reassured as not only am I not very RF, my experience with semi conductors is very limited too! I would also feel more confident using the perf board. I've been doing some research into making your own PCB's but feel its a bit outside my comfort zone at the moment although its something I really should try to get involved with.
Thanks also for the references for Spectrum. Their prices seem very reasonable. Regarding the caps, I have an account with Cricklewood who I see do stock the polystyrene caps although not the 270pf although I'm pretty sure that I have one or two in stock.
I'll definitely have a go at it and report back The advice regarding the coils and FET's is very useful, I'll check that very carefully.
Coincidentally David has very kindly reserved one of his FM/AM converters for me. This will give ultimate flexibility as I can listen to FM radio plus the facility to play MP3's and even Radio Caroline from an old smartphone. I certainly won't be short of things to listen to!
Thanks again