Please help determining suitable 01E transaxle (sorry)

Hello All,
I'm really sorry to rase this all over again.

My problem is that I've found a web site where one can order Audi boxes from dealer. When I reqest
information for transmission (2000 A6 for example) I get 2 boxes (5 and 6 speed)and numerous part numbers for both:

6 speed transaxle:

> 01E300047L
31/8 1 FRL,FPN
01E 941 521 1 FPN

# 01E300047LX
31/8 1 FRL,FPN
01E 941 521 1 FPN

> 01E300049
31/8 1 GBA

# 01E300049 X
31/8 1 GBA

> 01E300047G
31/8 1 FRG

# 01E300047GX
31/8 1 FRG

> 01E300048T
31/8 1 GAZ

# 01E300048TX
31/8 1 GAZ

> 01E300049G
31/8 1 GEA

# 01E300049GX
31/8 1 GEA

> 01E300049S
31/8 1 HES

# 01E300049SX
31/8 1 HES,GEA

31/8 1 FRF
01E 941 521 1

Than there are several 01X boxes - about 10 of them

And 6 OA2 boxes

Now I'm really confused with so many part numbers - what is the difference between them?
Which one to choose so it was used on the more powerful version?

Another question is about 012 gearbox.

How weake is that? Sorry, I forgot to mention that I'm looking for boxes for my own car project.
There will be two versions 250hp(240lb/ft) in 800kg car and 400hp version 900kg

So I was thinking - will it be possible to use 012 gearbox in 250hp version?

Situation with 012 is not any better - about 40! gearbox numbers offered /ubbthreads/images/graemlins/shocked.gif

All the above is for 2WD boxes only - millions of numbers for 4WD...

Thank you
Tudor Miron
Have a look at this site, the code letters can be made out, it also lists the vehicle it was used in, I would go for the biggest engined version using the box you require.

web page

Thank you Joe,
How ever I'm having problems with that site. For example looking at 2496mm^3Audi A6: Gearbox numbers are: 01EL 01EP 01E2 .... Only similarity with Part numbers that I've found is 01E than there is L or P or 2.... In my case there's 01E 300047LX...

I understand that I must be missing something very obvious. Sorry for such dumbness.

Thank you
Tudor Miron