can somone provide a link to load's of info about rx's, tx's and compatibility.

i plan on buying a sport arf and need rx and servos to go along with my jr quatro tx for the alpha 40 and i'm not looking to spend a bunch of money to upgrade tx.

what is your advice.

here are some of the info i'd like to know:

1, if i buy rx and servo's for a second plane to go along with the jr quattro for now, what componets will be compatible with an upgraded computer tx.
2, difference between fm and pcm, are they compatible?
3, can i run futuba rx with a jr tx?
4, digital servo's are they compatible with fm rx?