Question on polymorph forms

[molten_dragon]

I'm playing a sorcerer with improved familiar in an upcoming campaign and have chosen an imp. I've discussed the alternate form ability with the DM, and it has the following restrictions.

I can pick two specific forms that I can change into. They must be 3 HD or less, and can be any creature type that polymorph allows me to turn into.

So what are some good suggestions?

[Pilo]

Avariel (race of faerun) may be good, because you need a form that can be allowed in good society and they fly.

Otherwise there is a guide you can use : http://community.wizards.com/go/thread/view/75882/19871862/3.5Forms_for_Alter_Self