You can buy Zocor 10mg tablets over the counter - £7.99 (about $15) for 28 tablets (at Boots The Chemist - I work behind the pharmacy counter in a Boots store), so you wouldn't even need to wait on the NHS, you can go to pretty much any pharmacy and buy them. We'll sell them to you as long as you've had the tests and have been told to get them by the doctor.
You could also probably get them on prescription from a UK doctor, but again, you'd only need to wait a few days for an appointment (or even maybe get one within a day if there are free appointments) and you can get a prescription filled within a few minutes of an appointment as well (depending on where the nearest pharmacy is).
Honestly, I'm not sure if private insurance will cover it anyway, as you will usually need to use it for operations or serious treatments that have several months waiting lists on the NHS. I think private insurance companies require that you still visit the NHS doctors for things like day-to-day problems and prescriptions.