The thing is, with proxies and VPNs you're taking risks. Yes they can absolutely work as long as the proxy is truly private and/or the VPN gives out dedicated (not shared) IPs. But running an eBay/Paypal account on them is a whole different beast than trying to watch Hulu, for example.
eBay knows of all of the popular VPN/proxy providers and even some VPS companies. They can and will blacklist entire strings of IPs if they are certain they belong to a specific company whose users are abusing the IPs. With a stealth account, your ultimate goal should be to blend in with all of the "normal" (real) accounts, so that eBay has no way of knowing that you were permanently suspended before. People who use proxies and VPNs tend to do so because they have something to hide and because of that, those services naturally draw the attention of spammers, hackers, scammers, and the like - all of whom abuse IPs and can cause services to be blacklisted.
Checking to see who your ISP is can be done in a matter of seconds for free by anyone, so of course eBay with whatever sophisticated tracking technology they use has access to that information as well. Having your ISP say "Random VPN ISP, LLC" doesn't give yourself much credibility, especially comparing to everyone else with real accounts that shows up as AT&T, Comcast, Verizon, etc. Even if you get past their automated bots, chances are that one day you'll have to contact eBay, and that's where the problems begin. As an example, some new accounts face a temporary restriction upon listing their first item and you have 48 hours to call in or else your account is permanently suspended. This restriction is a piece of cake to pass, as they ask very simple questions and then look over your account - but if you're using a proxy or shared VPN, this is where things will go south. I've had to call in for customers quite a few times due to this restriction in the past few years and I've only failed it twice. In both situations the person was using a very popular shared VPN, the rep saw that, and then the permanent suspension happened.
With proxies and most VPNs, you're going to run into various security measures and problems that you wouldn't otherwise have to deal with. As another example, Paypal's infamous "sorry we can't send your payment right now" error tends to happen a lot more often when people use those two above mentioned services. And on eBay's side of things, I can all but guarantee you won't start off with high limits when creating an account with one of those services (and that's if you get limits at all - you have a high chance of staring a 0/0 limit account in the face either immediately, or after a few days/weeks after one of their bots randomly evaluates your account). And those problems are just the starting point. Really, you want to control as many aspects of the stealth process as you possibly can. Here, you are at the mercy of the proxy going down one day, or the IPs being blacklisted.
Are you located in the US? If so, then you have no real reason to use a private proxy for eBay/Paypal. The only upside they have is that they are cheap, but you can just as easily get a cheap VPS (not the best option, but it's much better than a proxy) for around the same price. It's the same with a VPN. There are some advantages to using a VPN (with dedicated IPs), like if you have many accounts and want to run them in virtual machines, but in my opinion that's a better option for someone not living in the US (and trying to run/create US accounts).
For US residents, I always suggest using a dongle/hotspot or phone tethering for running multiple accounts. Yes, you will usually get a completely new IP every time you turn the device on and off, but that's not a bad thing (especially if you want more than two accounts down the road).
The main things to worry about are: 1. the quality of the IP and 2. having cookies/history in place. Dongles/hotspots/tethering run off of the cell phone companies' network, so your ISP will be AT&T, Verizon, Sprint, or T-mobile. Yes, people can and still do abuse mobile IPs but it's much, much less than proxies/VPNs. And eBay can't blacklist those IPs without blacklisting nearly the entire country. As long as you have the original cookies and internet history, you can literally log in with a different IP address everyday as long as #1 still holds true.
You can also have two routers and swap them as an alternative, but that doesn't leave room for growth.
For non-US residents trying to create US accounts, then either a VPS from a company that isn't too popular, or a similar VPN with a dedicated IP will work best. You want to avoid the popular companies since eBay has them on their radar and the chances of a company listed on page 20 of Google having their IPs abused (and eBay knowing about it) is a lot lower than HMA or Hotspotshield.