[A4] 5- vs. 6-speed, 1.8 vs. 3.0, auto brokers

[Stephen C. Gibson 86]

Hello A4ers,
I have been a lurking wannabe on this list for a few months,
and am now ready to take the plunge to a4 ownership. I am
actively shopping for a B6 era Avant with sport suspension.
My preference is for a 1.8T with 6-speed manual, chosen as a
compromise of fun and (relative) economy, but I am curious
if any of you have opinions about 5- vs. 6-speed. I have
driven both, and think I prefer the 6, but they're harder to
find. Is it true that the 6 became available with the 3.0
only in '03, then with the 1.8T in '04?
Regarding engines, I have only driven the 1.8T and I think
it has plenty of power, but could always chip it if I change
my mind. I am curious about any opinions regarding the 3.0.
I have driven the older 2.8, which I think is a bit sluggish.
And lastly, I am curious if anyone has experience using an
auto broker to find a used car, as what I seek seems to be
currently somewhat rare in the used market (B6 Avant 1.8T
6-speed w/ sport suspension).
TIA,
Stephen