I'm going to be sparring this pressure fighter, he has an iron chin, great endurance, speed, and excellent ring generalship. How do I keep him from entering my bubble, and restrict his reach to only the tip of my glove/punch?

There's a good post by Thomas Tabin that you should read: Circling

By the way, I just uploaded a video of Hopkins in the ring describing some of the things that he does, and what he looks for: http://www.youtube.com/watch?v=Y9496vJdgiA It's very interesting, and you can see those same things that he's talking about in his fights.

[Note: This was directed at Olsen's prior post before editing which related to circling and Bernard Hopkins.]

Bump.

First off, I'd like to thank Chris for answering my question, the video as well as the thread was very helpful and informational.

I updated the OP with another question instead of making another thread, so could you guys answer it for me?

Depends on what your strengths are....George Foreman had plenty of success with Joe Frazier by turning him, using his momentum against him.

Keep him turning so he can't get set and get your jab working.

The jab or well placed uppercuts will have your opponent second guessing their swarming tactics

Don't jab down at him. This shortens your arms, gets him closer to your body, as well as allowing him opportunities to counter you 'over the top' with his right hand. Bend your knees a bit, widen your stance (front to back not side to side) and jab his chest. Hard to slip punches with your chest. Don't start your jab from too high- shoulder level, not from in front of your eyes. If you can find some tape of Bob Foster, watch it. He was very, very good at maintaining the distance he wanted to fight at.
Good luck.