Just a short background to how I got to where I am: My main purpose
is to record a classical vocalist(soprano) and piano in various
settings practice/masterclass/recital. I started with my old Marantz
420 tape recorder using a dynamic mic. This was just about enough for
the time being. I recently changed microphones to a Rodes NT3 and am
liking it a lot better. Very recently I purchased a Neuros HD/Mp3
recorder but without a preamp the recordings still work but the
results are quite disappointing (input via line in; levels are way to
low). I thought, why not use my tape deck as a sort of preamp only to
find out that my line out only seems to reproduce the mice in levels.
So now, here I am looking for a pre-amp.
It appears to me as if I have 3 ways to go he

1.) Keep everything very portable and get something like Shure FP23,
SD MP1 or Denecke AD-20 (These also seem to be just about as much as I
can possibly afford)
2.) Go with just a regular preamp and find myself a wall outlet. Here
I don't have any idea as to what to get. I've read that for classical
recordings I want to stay away from tube amps as to not alter the
sound. Is this indeed the case?
3.) Get a preamp which has all necessary connections to use my laptop
for recording instead. I'd like to keep the computer rout open but I
think it may be smarter for me to get a good preamp and worry about
the additional AD conversion if I get to that point.

Finally, just as I am about to overstay my welcome, any pointer to my
future plans will be appreciated. I figure since the performers are
highly trained, balance should never be a problem(between singer and
piano) and so any recording in "distant" should suffice and reproduce
a representative recording - am I way off base here? For this I
thought it would be wise for me to consider a stereo setup. would a
second NT3 work in a stereo setup or is the mic to directional?

At this point, keeping all my problems in mind, I'd truely appreciate
any help I might get!

TIA!