This isn’t quite a concise question, and I’m afraid it just looks like you are trying to find a pretext to get a Schengen visa.
You don’t decide you want to get a Schengen visa and then try to find out what story would work best.
It’s the other way around.
You have a good and valid reason to visit a specific country, and then you try to get a visa on that basis.
Tourism is one thing. Business is another. While you could do both in a single trip, at least one of the two must stand on its own feet, and at this time neither does.
Your whole business thing is just convoluted and even we see through it, so a trained consular officer is just going to reach directly for the “refused” button in less than 5 minutes (probably a lot less). Remember that contrary to the UK they don’t even have to write a page or two to explain why. They just tick boxes. I can already tell you they are going to tick one of reasons #2, #8 and #9 (probably several). Maybe also #3.
Do you even have a business? A sales network? Funds to buy the hardware, pay for shipping, duties and taxes? Have you even tried to find a single supplier in the country? Why don’t you contact them by e-mail or phone? Are you planning to just knock on doors? Can you even list one supplier? Why Iceland if you don’t have anybody lined up? Why Iceland when it’s one of the smallest countries in the Schengen Area? Why would you even consider buying from there when it’s probably cheaper to buy from China or other countries?
Oh, you don’t really have a business yet, you want to set one up in Iceland? Why Iceland? Do you have funds or investors? Do you have any local contacts? Do you know the language?
It just doesn’t add up. And you probably don’t have half of the paperwork required.
Remember that a visa is not a right. You have to convince them that:
- You have a legitimate reason to visit (nope)
- You have the funds to support yourself during your stay and pay for your travel back home (don’t know but somehow I doubt it).
- You have a good reason to travel back home and will actually do so before your visa expires (ditto, especially with the "I want to set up a company in Iceland" bit).
Convince them as in provide evidence. As in company registration, bank statements, tax returns, pay slips, information about your business, etc.
Remember also that:
- The "richer" the country, the more difficult they are. Iceland and Norway (which process the visa applications for Iceland for Nigeria) are among the richest countries in the Schengen Area (they're actually both in the top 10 worldwide)
- Nigeria is in the top 15 countries with the highest Schengen visa refusal rate (over 40%).
Do yourself a favour. Forget about the Schengen Area or any similar country for now. If you really want to do business, you can do it from wherever you are nowadays. You can sign contracts without even seeing a client in person. But you’ll need to have a real business to do that. And it’s probably much easier to start one in your own country rather than halfway around the world in a country using a different language.
Once you have a real business, getting a visa to go visit actual suppliers or customers is just going to be natural. Because it’s the right way around.