We use VAs for various tasks, some of them client facing and some of them not. We only hire full-time VAs though, when we tried hiring part-timers we found it really difficult to find a good one honestly. They often juggle multiple jobs and you can get put on the back burner or get really low quality work. You may evaluate if some of your client facing things like a client intake call, email correspondence, general phone answering/appointment setting could be handled by a VA so it would be enough hours to be full time. If hiring full-time I'd recommend Ataraxis. They are based in the US but have virtual assistants all over the world, a little bit more expensive than some options but I think they do give the VAs a fair cut. They only do full-time placements though.