Just browsed Pyramyd air for a while, there's a great deal on the Diana 350 Feuerkraft. If you want the most powerful, you might want to check it out
EDIT: I'll ad this disclaimer because I forgot it's not common knowledge for non-airgunners. Shooting this high above the sound barrier *MAY* make lighter pellets keyhole. With heavier ones (like the H&N Silverpoint) I haven't found any issues. If you want to shoot light munition too (like wadcutters for target matches), a lower velocity (max 1000 fps) air rifle might be advisable.
EDIT: I'll ad this disclaimer because I forgot it's not common knowledge for non-airgunners. Shooting this high above the sound barrier *MAY* make lighter pellets keyhole. With heavier ones (like the H&N Silverpoint) I haven't found any issues. If you want to shoot light munition too (like wadcutters for target matches), a lower velocity (max 1000 fps) air rifle might be advisable.