Free hosting won't work easily with phpVMS and some of the addon modules you may use.
Have you looked into vmshost.io ? It is run by the developer of phpVMS. Pricing seems reasonable. I know a few guys that use his hosting and they seem happy with it.
There are a lot of other good hosts out there too. While a VPS is nice, it really isn't needed.
As for your VA and phpVMS - I suggest you visit the phpVMS forums. Lots of help available there to assist you in setting up and running your VA.