Figuring out sterilisation

I need to get me a pressure cooker to sterilise stuff in, but I can't seem to find a decent size one here in my country. I'm wondering if the best way wouldn't be to get someone to help me build a steam barrel.

The problem is, we have frequent electricity blackouts, so maybe I need to get one that works with gas instead. I don't know.

There are some pressure cookers on the market, but I think they are too small. Maybe I should just buy one, see how it goes and then later upgrade to a bigger one.