Hi Blind Squirrel,
Indeed finding the right VA for you is not an easy task, but it is also not an impossible one. Here are some recommendations I have that hopefully you'll find helpful in finding the right VA for you.
1. Hire a Company than an individual.
2. Consider companies which offer a FREE Trial before actually paying for their services.
3. Do not just go signing up to companies just because they're popular. You could look for other more reputable companies that offer affordable rates yet superior quality services. I do know one from the Philippines in the name of Pepper Virtual Company. Here's their site:
http://www.peppervirtualassistant.com/
They do offer a FREE trial so you could actually have a firsthand experience before deciding if their services are perfectly suited for you. I've been tremendously happy with them and I'd like to share this experience with you. Hope this helps.
Best,
Rojae