You say you are just starting out, are you a complete newbie to window cleaning? Or do you come to it as an experienced window cleaner who has worked for someone else?
You have said you will be doing shop fronts and houses too, so is it an accurate assumption that you have bought, or are about to buy an existing round?
Have you looked into WFP? If you are doing commercial stuff you should consider it, as updated regs regards health & safety may affect you to a greater degree than if you were just doing domestic work.
But as to ladders, get an aluminium extention ladder, make sure it is a light trade one.
11ft extention is fine for standard houses, won't be long enough for a 3 storey house though, so at least consider a triple.
Also try to go for a ladder that has rungs that are flat when you stand on them, not square section or round section. It makes them far more comfortable to stand on.
A 3 metre pointer ladder is a biggy, I have 3 of them (but only cos I had others working for me in the past) two 8ft pointers and a 6ft one. (As against 2m or 3m)
The 6ft one is by far the most useful.
I've had extention pointers in the past too, they have their uses, but when they are well extended I would, in this current climate of health & safety issues, have grave doubts about their safety and stability.
Roof rack; make sure they are ladder bars as against a 'roof rack' (though I imagine you meant roof bars)
I'm sure you are now supposed to have the correct ladder clamps to hold your ladders in place.
But I still use a good pair of bungee's
Naughty me, but in 21 years as a window cleaner 10 years running my own decorating business I have never, ever had a problem with them.
They are not what you should use of course, though I will continue to use them...... but I can't stand the ladder clamps.
A final thought; If you are assuming you will pick up lots of shop fronts, then unless you really are buying into an existing round, then think again!!! They are far and away the hardest and most heavily contested work to get into.
Best of luck
Ian