UK CakePHP Development Partner Wanted / Hourly Rates?

Hi,
I've inherited a CakePHP custom web app with MySQL db and a custom API.
I'm seeking a development partner to support, maintain and develop the app and API for the longterm.
The firm must have multiple CakePHP developers, be well established and based in the UK.
I'm trawling Google for possible partners, contacting them and receiving hourly rates.
It is difficult to find valid, honest reviews of companies to assess their credibility, experience and value. It seems a huge risk to partner with the unknown.
Can anyone suggest a possible partner please?
Thanks!