I can only suggest you approach the condom companies and set up a deal with them. You get a life times supply for prototyping and/or modelling these new super condoms.
Condoms are made of latex, which stretches. The bigger you are the tighter the fit. How can there be a problem?
Sorry sfx999... i think I may have been too sarcastic!
Have you tried the wonders of Cling Film?
Get a windsock....
But seriously, there are ones for the larger gent, but unless you're blessed with over 7" girth and therefore should be in the medical books then any tightness is designed to stop it slipping off during sex. I had a similar problem with some makes and used the larger ones and discovered they were still tight. Since I'm not massively endowed, I figured it was to stop them coming off.
If they're still uncomfortable, find someone who either won't practice safe sex, or a girlfriend who you can shag without condoms.
Okay here's a final shot.
Casanova used the intestine of various animals, tied on with a ribbon.
Speak to your local butcher.