I almost found out the hard way. Long story on that one.
For the longest time, I had been running the Sveasoft firmware on a Buffalo WBR-G54 although it was an older version specially hacked to support it.
Essentially, the wireless portion IDs itself slightly different than the original Linksys WRT in the source code so long ago you had to add the Buffalo specific tags to find the wireless portion.
Anyway, I attempted to put Alchemy 1.1 on the Buffalo the other day since it natively supports it. For some reason, it looks like I might have bricked it. I can't even get it to respond doing the ARP/TFTP trick that you could use previously. I'll most likely have to pop it open and short the pins to invalidate the flash code.
In the meantime, I picked up a v2.0 WRT54GS and put Alchemy 1.1 on it. It was the lone v2.0 in a batch of v4.0s. Word to the wise, avoid the WRT54G V5 because it is running VXWorks now. You will want to grab the WRT54GS V4 if you want to put custom Linux on it. It seems that some V4s have 16MB of flash and some have 32MB. Right now it seems rather random, so I took the 'known good' v2.0 home with me.
Here is the cheatsheet for versions and serials, taken from linksysinfo.org:
CDF0 = WRT54G v1.0
CDF1 = WRT54G v1.0
CDF2 = WRT54G v1.1
CDF3 = WRT54G v1.1
CDF5 = WRT54G v2.0
CDF7 = WRT54G v2.2
CDF8 = WRT54G v3.0
CDF9 = WRT54G v3.1
CDFA = WRT54G v4.0
CGN0 = WRT54GS v1.0
CGN1 = WRT54GS v1.0
CGN2 = WRT54GS v1.1
CGN3 = WRT54GS v2.0
CGN4 = WRT54GS v2.1
CGN5 = WRT54GS v3.0
CGN6 = WRT54GS v4.0
The store had a ton of the CDFA models and CGN6 models. I think this one was left only because it came as a kit with a USB adapter. I have 30 days to return it so if I bump into one without the USB adapter, I might do so.
WRT54G v3.1 is the last "good" WRT54G and WRT54GS V4 is actually a WRT54G v3.1 rebadged. Confused yet? You should be. It is hard to keep track of.
The one good thing of these newer models is that it is one chip instead of 3 chips and they are rumoured to have stronger WLAN but call me old fashion, sometimes all-in-one solutions aren't as good as individual components.
Anyway, I'm rambling, but it is only a matter of time until I have Snort / Kismet / OpenVPN on this "old school" GS model. I'd still like USB onboard but those seem to only come on the ASUS models. I could run my cell phone off it then, so I still might go that route.