Networking problems

I have a wireless internet setup with my powerbook and my sisters ibook G4. My netgear router (which i purchased since January,supports wireless-N) has been acting so inconsistent (holding wireless signal for an hr), which has got me thinking that i should purchase an airport extreme. Is it even worth purchasing an airport extreme since my computers dont support the new Wireless-N feature? Or does it? i really have no clue as to what wireless-N is. all i know is that my computers worked fine when i used a router that supported the b/g standards. Could the reason why my router has been acting so crappy is because of my computers not supporting the Wireless-N standard? Was it a mistake on my part that i bought the wrong kind of router? Should i have purchased a router that supported b/g standards? or does that matter at all? Help....im planning to buy a new router by tomorrow and i need to know which direction i should be heading.