Whats the preference between Ikelite 5510.45 and a 5503 domes

I recently bought a couple housings on ebay to piece together a whole kit. So I have this massive 8in 5510.45 dome with the 4.25in extension tube. I also have a 5503 dome port. Ive booked a trip to Guadalupe Island next Oct and am hoping to get all of this dialed in prior to that. I shoot a Nikon D300 and I imagine my 10-24mm 3.5-4.5 will be the lens that I use. Only other one really would be the kit 18-70mm. So Im just trying to get an idea of whether or not I really need 2 dome ports and maybe what the advantages/disadvantages would be. Is the large one the more verstatile other than it being the size of a Frisbee?

Any guidance would be great.

Thank you much

Adam

Between the two, the 8" dome will give you less corner distortion. However, you will need the extensions that match the length of the lenses you plan to use. You might need two. Ikelite has a nice list of lenses and their recommended extension tubes. The 8" dome also saves some space if you have 2 or more lenses of different lengths. The only lenses I still have behind a small port are the macros (60 mm and 100 mm) with flat ports.

Here is photo with a 17 mm lens behind the small dome https://flic.kr/p/7vijSQ and the large dome https://flic.kr/p/znL4t5. I think they are both uncropped, but I don't recall.

Thanks for the info but I couldnt get those links to work. I do think I have the extension tube for my lens too for the 8in.