Port for Zuiko 7-14mm lens

I have an Olympus E-3 and housing and also the 8" dome port #5510.45 and port body #5510.25 for the 7-14mm lens. However, I find that the complete assembly (with 2x DS125s) is extremely heavy out of the water and uncomfortably negative in the water. Looking at the Ikelite website I see there is also a 6" dome port #5503.30 for this lens. What I would like to know is:

1. Are there any optical quality differences between the two ports?
2. Does the #5503.30 include a port body, or is a separate body needed?
3. What is the weight, in air, of the #5503.30?

I would like to reduce the weight as much as possible and at the moment it could be too heavy (and the 8" port fragile) to take being thrown around in a RIB. A smaller, lighter dome port would be preferable.

Any comments or advice welcomed.

Thanks,

Steve

1. The 8" dome will normally give you sharper picture edges than the 6" dome at super-wide angle settings.

2. It is one piece (6" dome and port body) with a removable shade.

3. .85 lbs.

Thanks Brett. That's settles things, I'll stick with the 8" port. I currently get soft edges with my C-8080WZ set-up and one reason for going to the E-3 was just this problem.

Cheers

Steve