Unfortunately, it seems that most modern publishers and textbook writers haven't seen the value of composition, mainly because they don't see the value of working toward fluency in ancient Greek yet. I am hopeful this will change, but I expect it will be a while yet before it does.
Meanwhile, here are some good sources where you can practice online:
1. ΣΧΟΛΗ,
http://schole.ning.com/ The online Greek writing community. Focus is on Koine, but Attic and other dialects welcome. Founded by our own Louis Sorenson.
2. Textkit,
http://www.textkit.com. There is a composition board there where you can practice writing ancient Greek.
Both places have lots of helpful people who will encourage you and give you tips on writing in Greek if you want them.
3. Also, you can do emails and private messages in Greek. You can PM me here or email to
dewayne.dulaney@gmail.com. I'm just at the beginner stage in composition, but I enjoy trying, and will be glad to correspond with you in Greek.
Hope these help,
Devenios
