White Label IT Support in and around London

I run a small IT company in NW London. One of my technicians has handed in his notice and therefore I am looking to use the skills of someone such as yourself to fill in the gaps in order to keep our level of support to our clients' expectations. We have a few clients who we provide remote support to and others who prefer us to provide on-site assistance. All our clients are locate in and around London but the on-site work is all in London. All our clients run Windows machines, some have WIndows servers too, a list can be provided upon hearing back from you.