It sounds like you are private sector, so any of the private sector unions will be good to contact. It is worth contacting and meeting with a few to feel them out. Bring a small team with you though, this is good for two reasons: you get other opinions, and you show them that you aren't just a single person trying to unionize a workplace. IMO (and to be clear, this is just my opinion) don't bother with the IWW, they basically don't exist. You need money, staff, and experience, and the large unions have these (even if they are libs at the end of the day--but being part of them does mean you can send delegates to conferences, etc.., and move them in a direction you like).
You will have to meet with the unions to feel them out, and I only know about public unions, so I don't have specific advice there. It really comes down to a few things, your local, your staff rep from the union (the person who helps you bargain), and the union itself. Make a list of unions that may be relevant to you (i.e. Canadian Private Sector Unions), and then look at whether they have locals who have recently been on strike, how much the union itself supported them, and the outcomes of their contracts. But do reach out and make contact with them (using your private email ofc). Starting your own industry specific union is likely not a great idea in such a small workplace.
IDK what province you are in, but that can have a bearing on specifics too.
This is very basic, but here is the CUPE guide for unionizing: https://bcorganizing.cupe.ca/process/. You already sound like you have the beginning of an organizing committee, so the next step is to solidify that, and then talk to unions to get advice in person.
A side note, but I was recently a party to a failed organizing drive of a small workplace, and it failed because the potential members where not properly informed and the organizers got ahead of themselves.
Yeah, public sector is heavily unionized, but not entirely, especially when it is in that weird public/private middle ground. I've been part of two different unions. Both had/have their issues, but in one case it was primarily a problem with the local. If you start a new local it is kind of nice because you don't have pre-existing apathetic execs who are useless. Even if you get unionized, the process of agitation doesn't end or else people get complacent.
When you meet with unions do ask them how they would support you on strike. For me, one of these unions basically gave us a blank cheque (though they wouldn't call it that), staff that were on the picket everyday pumping people up, and tirelessly worked to escalate. Part of this was because the president of the union itself was good, and we lucked out with good mid/lower level staff who had guts.
Solidarity and best of luck organizing!