do you want an umbrella folding pram which is more compact like this
http://www.baby-pages.co.uk/acatalog/copy_of_c opy_of_copy_of_PramsBebe_Confort.html or a flat folding pram where it only folds in one direction like this
http://www.mamasandpapas.co.uk/product_details .php?id=2594488&type=I ?
There are many good makes and a lot of pram combinations where the carrier will clip onto the frame of the pram.
One thing to take note of is how long you would need baby to be in the carrier. It is not recommended that baby be it for more than 1.5 - 2 hours at a time as it can affect the spine.
You need to make a sort of wish list of what youd like and then go to a local pram retailer and see whats available.
Will you be using it a lot? Will you mainly use car? What terrain will you push over (small wheels hate gravel) what will fit your car? What budge do you have? etc etc etc.