If you are think of getting a cutting torch, I'd suggest a Plasma cutter.
They are pretty safe compaired to gas torches and grinders.
You will need a compressor as well, but these days they are cheap and a investment.

I dunno how old you are though.

Grinders, used properly, are fantastic. But there's a lot to know about using them first. Soooo much to know.
To me its all basic common sense, and a bit of learning.
But I have seen people do everything possible wrong. Stuff I couldn't even think up.......

Gas torch, well that's a big boys tool, for big boys jobs, and you allways need to have a 'TA' around as well.
A 'TA' is a 'Tradesmans assistant'. If you ain't a Tradesman, well scratch having a assistant and having a gas torch.....
Yep, I have seen a few things go wrong with others using gas torches. Basic stuff too.

Plasma, its neat, its cheap to use, its a great tool and a great investment.
Just don't 'strike' it in mid air. Make sure its got a good earth and avoid blow back into the tip and the parts will last longer.
In my case, 8 times longer...... (I was working on a job, they blew out the tip, one of only two we had, in a hour. "That's how long they last" they said. I made the second tip last all day. They blew it out within a hour the day after.....)