Netgear RangeMax or Linksys Wrt150N

I recently replaced my DLink DL-524 with the Netgear RangeMax WPN824.
I have four computers on the network, one of which is heavily used for
World Warcraft. We had issues with the game when two of the other
computers were being used for other web apps.

So far the Netgear seems to have solved the issues. The connection
speeds of the four computers haven't changed but we haven't had any
issues with the game since I put the Netgear up. Also, I'm not
seeing the conflicts we've experienced before when the microwave or
cordless phones were in use. I'm wondering, however, if I should be
looking at something like the Linksys WRT150N.

My house is fairly large and I would like to extend the range of the
network. I have the router on one side of a large stone fireplace in
the middle of the house. Unfortunately there is no way to set the
router up without the fireplace in the middle so the computers on one
side of the house always seem to have a better connection that the
ones on the other side. I'm wondering if the WRT150N (or any N
router) could help me with my range issues as well as speed.

Any advice?

Thanks.