Can you buy from Amazon UK to ship elsewhere? The Amazon UK page tells you to go to Amazon US if you want to buy a Kindle that is to be sent outside of the UK.
The Kindle 3G+WiFi in Czech republic appears to have the browser restrictions when using cell connection. The Amazon US page lists it as only supporting Wikipedia and the Kindle store via the cell connection. You have to use WiFi for other browsing.
If you order a Kindle from the US and have it sent to the Czech Republic then it doesn't come with a charger. You can use any good quality USB charger however as the Kindle one isn't particularly special.
The US Kindle 3G+WiFi or the international Kindle 3G+WiFi should both work in the Czech Republic. The issue appears to be whether you get the US or international version. Amazon's
US Kindle (AT&T) coverage map shows it as being supported but only has 3G in the what I assume are the major cities. The rest of the country is GPRS/EDGE only. The
international Kindle (Vodafone) however only supports GPRS/EDGE speeds everywhere including the major cities.
If you're going to be buying a Kindle then get the US version or get it sent from the US. They'll automatically give you the most suitable Kindle for your country which should be US version. Don't get the UK/"international" version as you'll end up stuck with GPRS/EDGE. This is currently true anyway. Amazon may change it in the future.