This is a very interesting question. I can assure you, I AM searching for one.
The problem is that the majority of biblical scholars are religious, so one generally won't find too many secular biblical scholars to begin with.
But I'll look anyway. This might take awhile.
The fact is though, that most scholars do give an earlier date for the composition of the books of the New Testament, whether they're secular or not. I'll see if I can't find some articles. I'll be back.
Edit: I just finished reading this article (it's a PDF file, just to warn you) (yes, I know it says it's a PDF file in the link, but I still miss those sometimes); it cites several different books on the subject (which is the only reason I'm referring it to you):
http://www.scborromeo.org/papers/dating.PDF
Another interesting article on how the New Testament was dated:
http://www.british-israel.ca/Newtes2.htm
Here's another:
http://www.anointed.net/Libraryroom/Revival/RichardRiss/evidences/part1/12date.htm
For the record, I realize these probably aren't what you're looking for. The problem is, there's no such thing as a nonbiased source. Take each of the ones I posted with a grain of salt, and research them. Test them. See if they're true. Whether they're "biased" or not doesn't matter. What matters is whether or not they're the truth.
Whatever you find with the sites I posted, feel free to email me with what you think, either through here or at farkas419@yahoo.com. I'd love to discuss this further, and I promise I won't try to convert you. I already got my free toaster for converting fifty people. Still waiting on my new car... ;-)
I can find more sites if you'd like.