I cannot agree about Belkin equipment. I can personally recommend Linksys, and know several people who recommend Draytek. Netgear are OK, cheap & cheerful.
A combination router / firewall / wifi access point is presumably what you are going for.
Do you need an ADSL or a cable device?
802.11g (54mbps) is probably adequate for wifi, and likely compatible with your laptop wifi card. 802.11n is faster, but more expensive - and might require a new wifi card for the lappy.
Given that the LAN / wifi network speed will be comfortably in excess of your intenet connection, I don't think you need to worry about future-proofing in that direction.
SD