ask for help: OPT and H1B

I have a question regarding OPT and H1B and wonder if you could give me some advice.

I will defense in May for the Ph.D. degree. I also had a Master degree in
2003. I got an offer for the Research Manager postion (paid well, over six figures) from a small financial firm (80 employees) in Boston.
Since H1B of 2004 is used up, I wonder when is the best time for me to
apply for OPT and H1B? My concern is that if I apply for OPT now, then
I'll get OPT card in June, and it will expire in June 2005. If I can not
get H1B before June 2005, then I will lose the legal status in US since I
will deposit my thesis in August, which means that my F-1 visa will end
after OPT expires.

For my situation, I wonder what is the best strategy to do? Thank you very much. I am waiting for your help online now.