Portrait/Telephoto lens recommendations for a Pentax 67II

[Slvrgltn]

Hey everyone I know it might sound like a newbie question but I'm new to using a Pentax 67II camera. I'm planning on photographing Pelicans and other ocean birds for a current project I'm starting soon. I'm trying to get closer to my subject without spooking the birds away from me but I want to do portraits and abstracts of the birds. I'm only using black and white film for making large silver gelatin prints up to 30x40. Can anyone suggest a lens that I can use for this project? I already own a 200mm but should I buy a doubler for my current lens. Any suggestions from experienced Pentax 67II users would be greatly appreciated. I want to get close enough to fill the entire 6x7 frame without losing anything.

Thanks again for your time.

 

[mweintraub]

Do you know what FL in 35mm equiv you're looking for? I'd start there.
Some good info on the P67 lenses: Dead Link Removed

Would love one of theses: http://www.kenrockwell.com/trips/2009-08-nyc/19/IMG_2611-pentax-800.jpg