Like most diving in Norway, don't expect much service. If you find a commercial op, the most you can reasonably expect is gear rental, a taxi ride to the site and a site briefing. You'll be expected to rig your gear, plan and conduct your dive without anyone looking after you. And it's dollars to donuts that you'll have to BYOB (bring your own buddy).
I don't know of any commercial ops at Lovund, but there's a non-commercial diving club there. Now clubs in Norway are a bit more than US meetups, they are not unlike BSAC branches (albeit with less emphasis on formalities). They usually have a boat, a clubhouse and a compressor, and they go diving together. A club may - but most probably won't - have gear for loan or rental. The members may - or may not - be willing to loan out a tank and some weights on an individual basis, but plan on bringing your own drysuit (yep, dry. I don't recommend diving our coastal waters wet), regs, fins, mask, BCD etc.
That said, the coast up there has some pretty fantastic diving if you can get tips from locals who know the area and the good sites. Try contacting the
club at Lovund and ask them about what is and what isn't available.
Disclaimer: I don't know the specifics at Lovund; this is opinion based on general diving practice at the Norwegian coast. Make sure to double-check and verify (and/or falsify) any of my claims. Local conditions may differ...
EDIT:
Here's a business that apparently arranges diving trips to Lovund. Again, don't expect any service except the taxi ride and the site briefing