For cPanel you need at least 4GB of RAM and 1 2.4ghz + core and 7GB of space the installation so a 30GB disk would be a good size. cPanel is normally around $10 - Â£20 a month on top of the base VPS price.
You check your requirement online. I think there are so many hosting provider who provide VPS with Cpanel. No doubt there will be some terms and condition of hosting provider but you will get what you want.
The affordable solution not just based on the price of VPS+cPanel but you need to see whether its managed or unmanaged too. I know many providers offer free or give better pricing for the cPanel servers purchased.....so check whether the provider you choose can offer such levels of managed service with free or in reduced cost.
Affordable VPS with cPanel is relative to what you're willing to pay. What affordable means to me is quite possibly very different than it means to you, but maybe not. You don't give us much to go on. What kinds of specs do you require on that VPS? Managed or unmanaged? DDoS protection? SSD drives? RAM? Bandwidth? Special instructions?
If you are looking for cPanel with VPS, that means you are practically looking for a fully managed/semi-managed VPS server.
Considering price, in this case, will also be a priority but the specification of the VPS also matters.
But if you are looking at large disk space, then you can contact the host and request for a custom setting if it will be possible.
Meanwhile, you have to put in mind that requesting for custom servers usually attracts a high cost.