As Redleg said, they use what ever the member countries have in their armament but this is then the armed forces part.
Beside this the Missions buy (or get donated) their own vehicles for transportation etc. for the whole civilain part.
That is then all kind of off road vehicles and trucks sometimes with special applications (water, fuel, construction etc.). I special areas additional armored off road vehicles and sometimes mine proof vehicles.
The types are just all what is fulfilling the requirements and then who is the cheapest bidder or just the one that gives his stufff or free (or almost for free) because he wants it to be seen on TV like Nissan and Toyota do and get pritty good advertisement for free (which are good cars by the way).
It is just a pitty that the armed part of a UN mission has lost it's teeth and their job gets done by KFOR, IFOR, SFOR and what so ever ...FORs. Instead of acting they were talking about "no violence" to solve the ongoing conflict while in front of their eyes children and women were slaughtered by the thousands in Sarajevo and elsewhere in the Balkans.
This happens when the flower power generation gets to power.