Hosting and domain extension can help you rank good in Prussian Google searches. So if possible, get a Russian Based hosting + extension. Also use the option in google webmaster tools to set the geographical location for your site.
It is possible, but I think for security reasons it would be better for me to order both domain and hosting at American companies!
When you want to rank high in the USA than it's better to use a USA webhosting company. I think more important than hosting are links to your website. I've a website which is hosted in the USA and get quality links from german websites. Now it ranks on the first place in Germany and much worser in the USA. Another website of mine is hosted in Germany and some pages of this website get links from the USA. Exactly these pages rank high for the keyword in Google USA now.
Ok, I would like to have hign rank in Ukraine. Thanks, I will take into account your advices and experience and will add incoming links to high quality Ukrainian resources only!