2009 MacBook Pro 15 inch display upgrade
This is not going to be possible. Each display is not just a display, it's an entire display module and the whole module needs to be compatible (e.g. cabling connector and length, hinges, etc).

You could get more than the native 1440x900 resolution by using an external monitor (up to 2560x1600), but I'm sure you'd already know that.