I think your approach (VM+3G) is a good idea.
With a VM you are going to get new hwids, and PS will see this hwids, but they will see that you are running the client in a VM. Although this is not enough to ban you.
I think that you don't need a new computer if you can use VMs.
If you are worry about the fact that PS can get your real hwids, even using VMs, you can use online VMs and install the PS client there, but you have to pay for the service.
I recommend you to read the following post where people talk about the use of 3G devices to get new public IPs:
viewtopic.php?f=26&t=2702And this one where nefton talks about VMs:
viewtopic.php?f=26&t=2643