freeradius + LAN + auth + bandwidth (+ PPPOE?)

[TwoMan]

Hi All,

I would like to use radius to authenticate our users (using desktop pcs) 
on our lan, and give them access to internet based on their 
authentication data. (to give them bandwidth). I am planning it using a 
pppoe server, and then our users will use a pppoe client (eg. rasppoe) 
to make the connection. Clients can be linux,w9x,w2k,wxp
Is it a good plan? :) If there's a better solution, could You tell me 
what it is?
Which pppoe server is good enough to use for large number of users? (eg. 
Roaring Pengiuns'  RP-PPPoE server?)
How can I control their bandwidth?

I could successfully install freeradius wisth myql backend, and I can 
use this to authenticate our wifi users, so, the basics of freeradius is 
ok. But this time I have to authenticate lan users with oridnary 
ethernet network card.

Thx

TM