11n is the up coming but it's a year off before the std is ratified and several months past that for hardware. So I would not even look at 11n, twice the price and and then you are there beta tester. There is a lot oc conflicting data on speed and distance. Real case says distance NOT, speed some do, but require same mfg hardware for it to work. Not a good neighbor with 11g systems.
So save your money for now and stay with 11g.
Liksys has kind of shot there self in the foot, or should I say sisco. If you can find a v3 WRT54G, latch on to it. Load wrt and your set.
I do not like combo units. I use SMB VPN routers with a seperate AP. Like Netgear routers, USR5453AP, Dlink switches. I support them all.
All can be extended with repeaters. I prefer designing one system right so I don't have to mess with them.