Caro Luispipe, actually neither sounds great.
The first sentence doesn't work at all. I would amend the second as follows:
My academic background is excellent (note two "l"s in excellent):
I was awarded the _______ grant to support my research in __________ (or I received the ______ prize for my research in __________).
What I'm saying is that you need to put the supporting evidence for your "excellent academic background" immediately after your claim.
(One's GPA is usually just indicated on the C.V., without bragging about it separately in a cover letter. If you need to write it separately. I would make it the last sentence of your paragraph, after the more important information about your rewards and your research.)
Good luck in your job search!