Self-contained 1-bed/studio, furnished, z1/2-3

Hello there :)

Nb. I am not looking for a room in a flatshare. Please only respond if you are a landlord of a flat. Tx.

I am a freelance graphic designer looking for somewhere self-contained, lovely, secure and warm, long-term for myself. Prefer furnished, and no basements or ground floors. No garden needed, and no shares. Needs to be a proper flat, with bills and council tax in my name.

Current tenancy in SW6 expires 6 Dec, but I will happily move earlier for the right place, which for me will have a kitchen with washing machine and proper oven, bathroom, fast broadband/fibre (or the ability to set that up. (I need it for work 24/7), lounge. Furnished preferred, but will look at options depending on monthly rental price. It needs to be in a quiet and residential street. What I do generates zero noise, so I'd prefer that to be the case around me too. Overlooking main high streets and railways, or under final approach to LHR... it's a no.

Compact sizes are fine, as long as I can fit a desk, office chair and a computer in there. Outer limit: zone 2/3 borders.

I am NOT looking at shared flats, house-shares, buddy-ups or properties with included communal space: I want somewhere self-contained where I can live and work. Top end: ?1300 pcm. Normal tenancy agreement, gas-safe / electrics / heating / water etc, please have stuff checked and legal. No sublets. Landlord and accountant/ bank refs all available. Credit rating seems to say 'good', in part down to having bills in my own name, so I will need to continue that.

Ok, me: I am a 52 yr old adult. I have owned, developed and let my own property in London before, so I know how it works for both sides. I work for various publishers in town as a book designer & typesetter. V happy to provide you details?I enjoy what I do and love the people I work with. I am friendly, open, intelligent. I may even pay you a few months' rent up-front if that helps you... It depends on the place, really. I'd like to be there for at least one year, maybe two. I am leaving the current studio after a stay of 3 years.

Agencies: I am on rightmove and zoopla and have all the alerts I need, so you'd hear from me on there rather than here. If I don't respond first time round, no offence, but it's not right for me.
A