You will first have to pass oficer selection and then sandhurst. Before you finish sandhurst you will be asked for your choices of regiment or corps and a selection process goes on where you are interviewed by each of your choices. There is also the matter of medicals and initial weeding out flying experience. If they like you then you are in. That is a year down the line. Then you have the pilots course. There is a 50% failure rate on the course itself which is another year. After that you will probebly only get a single tour (3 years) to fly and then the reigns are pulled in and you will more than likely end up behind a desk.
That at the moment that will only have you on about 1000 hours.
Get a civvy sponser and you will probebly have at least 3000 in the same period of time. (5 years).
Leave it up to you.
But if you want to get anywhere within the AAC then you will have to visit an AAC unit near where you live. It will benefit you on your selection potential and you will see and speak to the people with all the latest info.
Best of luck with whatever you choose.