Purchase New AP? Asus RT-N66U or AEBS?

[Val-kyrie]

Hi all.

I am currently running a Linksys WRT54G v.2 stock FW. I currently have a 10/1Mbps connection via Time Warner, but I receive closer to 15-20Mbps down thanks to my Motorola SB6141.

I have been thinking about purchasing a different router so I can have a guest network and right now the AEBS and Asus RT-N66U are both on sale for about $140 (see techbargains.com).

Two questions:
(1) Will an N-router provide more speed than my current G-router or is the 10-20Mbps down within the ability of 802.11g?
(2) I own a MB and an iPhone and my daughter has a DS. Any thoughts about which router to purchase since our household is primarily Mac-based?

[Edit: Only other consideration is that I would like to set up an NAS to be an iTunes media server and DVD/BD repository which I will hook directly into my DLNA BD player. Can the AEBS read media files from an NAS?]