You're going about this wrong. First off, there's no practical way of doing what you want. Secondly, Google doesn't really care about what country you're hosted in. What they care about is which country your website is targeted at. If your site is aimed at Americans, then they might rank you higher in an SERP on Google.com than a site aimed at Brits with the same PR (your PR isn't affected by which country you're hosted in, only how many backlinks you have).
Now, what Google uses to determine which country your site is aimed at includes your IP address, but that's not the only (or even most important) factor. Google also looks at your ccTLD, and the actual language your content is written in (you might also use the
Content-Language header/meta tag and the
xml:lang attributes in your HTML to specify the region you're targetting—e.g. en-US or en-GB, but according to John Mueller Google has learned to ignore these hints since they're often incorrect). Of these factors, the actual language your content is in is the most important and then your ccTLD. Your IP is only relied upon if you have an international TLD. So if you have your content localized to the region you're targeting and you have the proper ccTLD, then that's more than enough to tell Google who the intended audience for this site is.
There's also no reason to trick Google or create an "illusion". SEO isn't a war against the search engine. After all, Google has a vested interest in getting your actual intended audience right. That's why, worse comes to worst, you can always specify a country for your site to be affiliated with in Google Webmaster Tools. This overrides any other factors Google uses to determine your target region.
So to wrap things up, Google isn't trying to slight you or your business. And their geotargeted SERPs actually benefit businesses like yours that have localized websites for different regions. You don't have to worry about your PR.
I forgot to mention that Google may also use your backlinks to guess at your targeted geographical region; this is probably less important than your ccTLD but still more important that your IP. So if there are lots of UK websites linking to your site and very few US websites, then Google can tell that your site is likely aimed at UK audiences.