i did something similar, but i just formed the grille out of that gutter guard stuff, without a border of any kind. it looks alright, i like the no-logo in the middle look, although yours looks good, too.
i have two ideas for a grille:
1. put my OEM grille back on, and just put the gutter guard on the back with zip-ties.
2. cut the middle parts out of my OEM grille, like what shook did, and put the gutter guard in there. the only problem is that i want to be able to return the car to stock, and so id need to get another grille from a junkyard or something like that.
my $0.02