linksys WAG54G as a simple access point ?

I have 4 devices here:

- Linksys WAG54G (ADSL modem + built-in WLAN router)

- Telewell TW-EA200 ADSL external modem

- D-link DGL-4300 108Mbps WLAN and Gigabit router

- Asus WL300 pocket size AP.

My house is on 2 floors, and most desktop computers are upstairs. I need
good WLAN coverage on both floors.

I am planning to install the TW-EA200 ADSL modem and D-LINK gigabit
router upstairs with computers wired to the gigabit ports,

Downstairs I plan either to use the small ASUS AP (802.11b, wired to the
gigabit router), or if possible the Linksys box (802.11g).

I am not sure though how to use the Linksys downstairs. Should I use it
to "bridge" the upstairs' WLAN with the downstairs WLAN and wire the
downstairs computers to it? The WLAN bridge could be slow...

Should I wire the linksys box to one of the gigabit ports, and configure
it as a simple access point? Can this be done or do I need something
like the D-link DWL-2100AP ?

Suggestions appreciated.

Lorenzo