Which dome for fisheye?

I am in the process to upgrade to full frame (Sony A7) and need some advice in the dome port department.

I am looking for an ideal port for fisheye lenses (various solutions, converted 2/28 at first).

Am I looking the right place with these?

Ikelite 200mm,

Seacam 160mm fisheye port,

Zen 170mm

Does anyone have experience with the Seacam? It it worth the price premium vs the Ikelite/Zen?

(Housing is undecided yet)

Dome Ports have a very close relationship with the lens behind and the housing as the housing can vary how much the lens "stick" inside the dome,

The process of buying the perfect dome port is:

1° get as much information regarding lens/dome combinations

2° Check dome port availability for your lens and housing you would like to have

3° start to exclude combinations for size/weight/price/servicing reasons

4° If you are lucky you may borrow the dome you wish to have, try it!

Generally speaking: s bigger the dome is, less troublesome he will be regarding corner sharpness and can be with different lenses

Minidomes are very handy, but you need the right dome for the lens otherwise they bother with soft corners.

You may ask Ryan from Reef Photo and Video and Zen Domes, he is the Guru regarding domes!

Chris

#1: is in process right now:) Problem is, that there is no native fisheye for FE mount, exact combos (e.g. fe2/28+converter) will be difficult to research. Nauticam has the N120 on their chart, however its review didn't convince me, I probably want go with a larger port.

#2: one housing candidate is the Easydive LEO 3, where the manufacturer provides port converters. However, these converters add some length and the port charts of the dome vendor cannot be applied...

Easydive also sells ports, however thinking on resale possibilities I guess I'll be better off with a better known standard, like Naughty-cam or Ikelite. In case Ikelite comes up with a housing, Ike ports sound the most practical option, however I've read about issues with their 8" dome vs fisheye:(

#3: Have to think it over... However feeling young and fit & resourceful in hiding HUGE things in HUGE pockets to save luggage fees, i am a bit less concerned about this:)

#4: Will give it a try!

One option besides the ports is the WWL-1, however it is also a beast.