So this stuff is pretty rare in my findings. Most giantess artists tend to leave the males inadequate to the situation. I think there are two primary artists that don't leave their big women hanging.
BustArtist:
He has many examples at his site. I highly recommend supporting him with cash. Specifically, you will want to look into his Grow Comics #2 and #4. Also look for some of his OLD comics. (One involving a genie, and one involving a growth ray gun.)
Miasma:
He has old stuff that he has made free and has posted in the BE forum with an epic example of this exact topic in the last year called "Large Attractions".
http://www.process-productions.com/f...ad.php?t=24355
I'll dig more into what I might have buried. As a fan, I'd love to hear from others about their finds.