i dont want to let my customers down if I can help it as still trying to build up a round and a name for myself.
Just because you won't clean a window because it puts your personal safety at risk does not mean you're letting a customer down. If your customer is even a half-decent type, the last thing they'd want is their new window cleaner having an accident and killing himself; attempting to get a peice of glass clean.
Try the stand-off. Try also a Rojak Ladder Stopper (£30 plus vat).
Personally I wouldn't attempt the window from the inside; as I find inside jobs like this a pain to do. You'd be making a rod for your own back. But that's just my opinion. When the winter comes; your feet are muddy and you've ten layers of clothing on; the last thing you want to do is mess about with protective overshoes and removing belt kits and clothes.
Anyway, most window cleaners take risks when they're starting up; like I did; because I/we didn't know any better.
But you don't and shouldn't have to. If it's not safe; just don't do it.