Help: OPT to H1B

Hi, I am a fresh graduate currently in OPT. My company agrees to sponser H1b and asks me to prepare materials.
My OPT expires in Jan 2005. I don't want to lose the OPT tax exemption benefit, but I also want to guarantee a H1B quotas. I have two questions:
1. Can I request my H1B to take effect 6 months (or more) later if I submit my application now? What might be a reasonable time to submit H1b application if I want it to take effect in Jan 2005?
2. Is Software Engineer a good title to be used in application?
3. Around what percentage of 2005 fiscal year H1B quotas has been used up?

I would very much appreciate anybody's answers and help.

Thanks.