Hi-
We are going to be traveling two-up through the Balkans. we are purchasing an unknown make/model in Prague, and will need to insure it for the following countries
Czech Republic
Slovakia
Hungary
Serbia
Kosovo
Montenegro
Macedonia
Croatia
Austria

(possibly Bosnia and Bulgaria)
Any any any advice on anything paperwork-wise with this region would be extremely beneficial!!
any notes on border crossings
carnets useful or not
etc. etc.
thanks so much!
Hannah and Boris

Hannah & Boris,
(You would get more replies by posting this question as a new/ separate topic, because your question(s) are only a bit related to "Bosnia insurance")

You say: "...we are purchasing an unknown make/model in Prague..."

Most EU countries require that, to purchase a vehicle, you must have legal residence or status in that country. I don't know that the same rules applies in CZ, but you should first be sure what the CZ rules are about buying/ registering/ insuring a vehicle.

Assuming you can legally buy a vehicle in CZ, it will be registered in CZ, with CZ plates; and insured by a company or agent in CZ.

Only a CZ insurance company/ agent can tell you for sure which of the countries above are included in a motorcycle policy issued in CZ. Any countries above not included in a CZ policy, you would have to buy separate insurance at a border crossing--assuming separate insurance is available at a border (which it sometimes is; and sometimes not).

A carnet (CdP) is not required in Europe--for any of the above countries.

In general, any bike that is registered in any EU country has no problem with border crossings in Europe, so long as you have a current vehicle registration, passport, drivers license, and vehicle insurance document (if asked)
You will find lots of other/ more specific border crossing info by doing a search on HUBB.

Archival Note:

More up to date information (as of summer 2014) about insurance prices and availability in the countries of former Yugoslavia can be found at this discussion:

Balkans Insurance - Here's the story, with details & sample documents

Also, apropos of the very first post on this discussion (from 2010), I attempted to enter Bosnia from Croatia at the Metkovic crossing on the way to Mostar in August of 2014, there still was no Bosnian insurance available for sale there, and the border guards would not let me enter without insurance. Hence I had to ride 100 km further south where insurance was available, and enter Bosnia there.

Michael