how can i make this statement better?

The word “you” is used too much. Also, your first sentence is quite redundant–expressing appreciation and gratitude is thanking someone. In addition, you’re pretty vague here–what chance? A job interview perhaps? Then say so. Be specific. I would do something like this:

I would like to express my appreciation and gratitude to you for giving me the opportunity to interview for this position I will do everything possible to insure success in this job.

Would you prefer that I can send a copy of my certificates to you via e-mail, or that I bring them with me when we meet?

Dan,

You say “If you require, I can send my certificates to you via e-mail, or alternatively I can bring them with me when we meet.”

The only words I would change are “If you require”.

Change the sentence to “Shall I send my certificates to you via email, or bring them with me when we meet?”

Don’t forget the question mark at the end of my sentence revision.

That’s perfect. I wouldn’t change a jot.