you need to go try out things in shop. go to several pram shops as they dont all do every make.
you sound like your after something with a carrycot for when lo is a complete infant.
pick one that uses a maxi cosi car seat (there are loads quinny,icandy,bugaboo) as these car seats fits almost all cars. but you will have to try this out anyway. i've never struggled with the maxi cosi in the huge variety of cars i've used mine in. the silver cross one struggled with some seat belts. and had to be installed and baby put in afterwards which is a pita.
and the maxi cosi is very easy to sell on.
pick something with a carrycot and seperate seat unit as usually the pushchair is much more compact once you get to the pushchair stage and finish with carrycot. i know they claim you have more pieces taking up space in your house. but at the end of the day you can just sell the carrycot.
the quinny buzz and icandy are good examples of this whereby you can pick up a great package deal in sales. then make a decent price sellin on the car seat and carrycot when you dont need them.
the great big pram types where the pram carrycot converts to the pushchair (i.e silver cross and babystyle) do look tempting. but in reality they are huge and really awkward and when you do decide you've had enough and need something lighter you wont be able to sell it for love nor money.
if you go to products section there is a pushchair chat.
go to shops try out a few. come back to pushchair chat and someone in there will have had what your looking for and give you an honest opinion on it's good and bad points. and you can decide for youself if its right for you.