Could someone help me please????

Ok, so basically I want to become a member of the illustration team and My audition has been posted, but someone told me that I need to use an art program. I used to use MS Paint but I don't feel that's a good enough program, and plus, once you save a picture it gets all blurry and crud like that. These are some of my sketches and stuff -

I have already ordered a drawing tablet and it should arrive around March 2nd, 2012. The tablet comes with a program called "Art Weaver" and I need to know if it's only the line art that has to be done on SAI Paint Tool. If sketching has to be done on SAI as well I need to find a way to download the FULL version of SAI uncompressed, that works with Windows Vista, and it has to be free because I can't buy anything besides my tablet. I just want to be a part of this project, so even if I don't get into the illustrating team please tell me if there's anything else I can help with, OK???

I can offer a zip version of my PTS or just a download link to a zip of Full SAI. It's not a very flexible program when it comes to vista and Mac unfortunately. -.-

oh it's not compatible with vista?
You can use GIMP? It's free. It's like a free photoshop. XD

And as for illustration team we need colourists. You don't have to worry about lines or sketches.