Hi,
can you please guide me in buying the engine and the transmitter and the receiver and the servos also there is a Futaba S3001 servo drown in the plan can u help me buying it from the internet with all it's parts i'll need...please help buying all parts but kits cause I am building the kits from the plan which i have...
MY AIRPLANE SIZE IS .45 WHICH I AM BUILDING

a short Brief:

What i need to know:
1-How to choose the engine with all it's parts.(size)
2-How to choose the servos for the wings the taller one and the smaller one. (for the back wheel i know that its need Futaba S3001).
3-How to choose the Transmitter/Receiver also the battery(for the nitro RC airplane).(the brand and 4 channel or 5... i don't have any idea about that so guide me please)
4-How to choose the Engine cowl also the landing gear also the canopy.(sizes)

sorry for all of this questions but i really need a detailed answers because I am so newbie!!!

Is this your first plane, if so stop there. Get yourself a trainer. There is a list of good trainers at the top of beginners thread.