the oils are good quality and they also stock a range of organic essential oils. They ship worldwide.
Musk disappeared in the 90's, restricted for sale to the general public for various reasons. You can get hold of synthetic musk perfume oil though.
An essential oil is the pure plant oil, a perfume oil is generally a synthetic similar to the natural smell. I have never seen or smelt a true apple essential oil, they are synthetic perfume oils. Strawberry is available as a perfume oil. The citrus are available as essential oils. I would recommend buying the true essential oil over the synthetic where possible, especially with jasmine and rose. (while we can still buy them >: l - but that is for another thread...)
An absolute is the result of solvent extraction as against an essential oil that is mainly produced by distillation.
To find specific rare oils try googling the name, in the past I have bought oils from the US as I couldn't (then) find them in Europe. Be careful - a lot of stores sell perfume oils (ie synthetic) as essential oils.