key length for smart card key generation

[Anonymous Remailer (austria)]

Hello,

I am able to use the gpg2 --edit-card to generate a 2048 bit secret key
on the card and the stub in the local key ring.  Encrypt/Decrypt
functionality seems to be working.

I read two other old posts on this list that seem to indicate that this
is all gnupg supports:  
* You cannot import existing secret keys to the card
* You cannot choose different key lengths for the keys

Is that correct?  Do I need to use a different tool to put 4096 bit
keys on my card?  Can anyone recommend which (free/linux/unix) tool to use to 
manage keys on the smart card?

(When I try to use the gpg2 --edit-key, and then keytocard, I get an
error saying importing keys is not supported).

Thanks