Intelligent business assistant in London (ongoing)

I am currently running a small technology company (software development) and a family-owned (non-tech) business in London, and I have about 3 dozen side-projects that are all in need of time, attention, organizing and moving forward. I'm looking for a very flexible and well-organized business assistant with the following must-have qualities:

1. Excellent communication skills (written, spoken, listening, note-taking, etc.)
2. Very well-organized with attention to detail
3. Some amount of business education & experience (esp. international)
4. Flexible schedule and available to attend events and meetings, with or without me, around London (also, presentable and with good networking skills)
5. Keen interest and understanding of new technologies

The following are not absolutely essential but each would be considered a big plus:

+ At least one foreign language
+ Some background in finance / accounting
+ Any advanced IT skills
+ Social media skills
+ Own transport
+ Ability and willingness to travel with me abroad, occasionally

This is a long-term, ongoing job, with opportunities for growth for the right candidate, but probably not suitable for most who would consider themselves "personal assistants" - I'm not looking for a mindless monkey that can type at 90 wpm. I'm looking for someone who likes to think and make things work and help our businesses grow, benefiting from this in the process.

Ideally, you would be able to meet with me in west London before taking on this job.