Gliding Flight Simulator

I have been cruising around cyber-space looking for
an accurate flight sim while the outside tempurature
hovers around -20 degrees C. I am a licenced glider
pilot so I am particular. I have currently found three
possible software packages:

1. Microsoft FS 2004
2. x-plane v7
3. SFS v 4 (soaring flight sim)

I am interested in realistic tow plane flight as well
as thermals and realistic handling of a Schweizer 2-33A.

Of the three software packages (or any others not listed)
which offer:

1. Realistic tow-pakne take-off
2. Realistic tow rope release
3. Boxing the tow-plane
4. Rope-break
5. Tow plane upset.
5. Realistic spiral / insipiant Spin
6. Downdrafts / Thermals
7. realistic spoiler effects.

Thank you in advance,

Martin
Canada