KNIEVEL77
It really depends on whether or not you can afford it. I believe the average is approx 70 - 80 hours ( but i stand corrected on this ).
Then you may wish to take additional training after you get your licence.
I did a 44 conversion straight away and fly once a month with an instructor practising autos and improving general handling.
I found the whole SFH thing quite strange to begin as you really have to have targets to aim for otherwise your flying suffers. I started visiting airfields i knew from my training and cross country and then visited a couple of new ones, gradually flying further.
Carrying passengers is also a whole new ball game. Apart from their nervousness at being a passenger in something like a 22 its their mate/relative etc flying them and they know you've only just qualified.
After 12 months i'm not sure i would tackle something like Silverstone without being accompanied. Its more expensive to have someone sat next to you but you may feel its well worth it !
Enjoy !