aDSL and Telstra (again :) ) - Australian issues?

[carl_(_at_)_bl_(_dot_)_echidna_(_dot_)_id_(_dot_)_au]

I've just ordered an aDSL link from an Australian carrier (Telstra bigpond), 
and told them I'll be using win98 on a laptop (which I will be to
start with, they only support installing it to a win32 or mac box ...).

My current connection is a pppd link through a Toshiba 420 CDT (P120, 40MB)
laptop using a 28.8k external modem, I'm going to upgrade this from
OpenBSD 2.7 to 2.8 on or about the first of December, and I guess then I'll
cut over to Brian's userland ppp to drive PPPoE (which Telstra uses ...).

I'm going to then be setting up an IPsec VPN over the aDSL link to my work
office, so I'll have IPsec over PPPoE/ppp over aDSL.  

Has anyone done this and have any success stories to tell?  I know that the Telstra
aDSL service works with some current version of GNU/Linux (RedHat 6.2 I think, with
a PPPoE package on it).  I am concerned that the P120 may not have the grunt to
keep up with a 512k link doing IPsec and PPPoE over ppp. Userland, that's
going to be a lot of context switching? Esp if I also keep running IPFilter.

Any comments?  Caveats?  I have a spare SPARC IPX I could possibly set up as an
OpenBSD 2.8 box to do the IPsec stuff, or possibly a SPARC 2 (I know .. museum
stuff, but they still work just fine :) ).

Thanks for any suggestions,

Carl