How best to take on debt in this situation?

I don't have any debt atm and would like to get some leverage on my stocks, savings etc to fund a small property investment abroad. Let's say I have €300k to work with and 25-30% would be perfect.

At €300k I couldn't find any Lombard loans or similar just yet, and traditional mortgage is tricky as I'm EU tax resident but the property is outside EU. Also, I pay myself mostly in dividends when needed, i.e. no salary or 'regular employment history' banks would like (at home or abroad). Plus letting a loan against the future property unlikely as I'm not a resident of that country. Doh.

Options I'm aware of-

1. I have an IBKR margin account and in EU can't withdraw on margin but could use some of my own cash for the purchase + borrow on margin to reinvest the extra into the portfolio.
2. Box spread. Confident I can learn the mechanics but could mess it up (new to this).
3. Unsecured personal loan. I've seen offers for up to €50k for 10 years, 5-6% APR. Interest not ideal obviously and not sure if I can actually get it (no salary). If so this would be for a part of the funds.
4. Borrowing from friends and offering them above-market interest. I'd be happy to pay them more than they get on their savings (and of course pay reliably!) but not sure how to formalise and make this official for them.
5. Anything I missed?

Or any advice/guidance on which of those options is better/worse than others?

From what I understand, 2. would be lowest interest but I'm ok to pay more if it's safer or easier. Thanks!