E-commerce website

As a sole trader specialising in supporting my clients develop efficient health clubs and spas (www.spabusinessdoctor.com) i am looking to develop my business growth potential through an online resource shop. This site (logo attached and domain owned) will retail a vast range of products and resources such as business development books, audio, e-books, DVD's from preferred suppliers and some that i have and will continue to create myself. It will also sell training course dates, experiences at some of my clients venues, spa furniture etc....all supporting spa and wellbeing and directed primarily business to business.

I like sites such as:
www.theyogashop.co.uk
www.naturalmagicuk.com
www.timetospa.co.uk

Although i am NOT a corporation or ltd company. BIG ideas with a much smaller budget. With this in mind i would not be adverse to possibility of commission /royalty % on sales over an agreed period of time for an expert company experienced with successful e-commerce sites who would be prepared to accept sole trader style initial project fee and 'invest' time and expertise for the future royalties.

The site must have the same polish as my current site does (could even take on same style identity / layout) and maximise the brand logo already developed. I would prefer any audio content to be able to be sampled and the option of download or hard copy sales on items where necessary (ebooks / audio). I must be able to edit and update the site easily myself post production. The site must also have capability to grow and develop as the brand does.

Capitalising on advances within e-commerce developments and latest techniques are also going to be important for long term success of the brand.

Further details can be discussed and detail formulated when successful bids have been shortlisted.