I mostly run it at max 800 and I don't think it's too loud, I've never heard any high pitched noises coming from it while on any speed.
I have probably done a few hundred garments on it so far and its great, such an awesome bit of kit. The lowest I've run it at is 600 and it's ok at that level, but even at 800 in a retail shop you wouldn't have to shout over it, it really isn't that loud.
If you need digitisation I found David Sharp to be very good, they are expensive at £12.50 + Vat per design but ultimately their service is great.
Adam