Hi sophhx,
Take a look at Payot and give their products a try. Alan Howard are the official stockists in the UK. I am also a sole trader with few clients I was in exactly the same position as you, I didn't want to take on a big load of stock as an opening order just in case it flopped. Needed an upmarket brand to use with my advanced facials and I wasn't disappointed.
Their galenic, natural and herbalist roots combined with their scientific laboratories produce very well researched products that are caring and effective. Less of the essential oils route with this brand unlike Decleor.
Start by ordering the essentials, they do trial sizes/or discovery kits with several items in them so that you can get a feel for the brand.
Their training institute is very good which can be done online for experienced therapists (not newbies)
Brand training and familiarisation of the new treatment protocols has upped my treatment menu and has made my business so much better. Their 42 step facial massage is excellent and body massage choices are really good.
I'm sure other geeks may make appropriate suggestions, but try them for yourself.
Best of luck.