Don’t buy a cheap one, lol. Get something that at least takes Victor or Harris parts if not one of those two brands. Cutting tips and welding tips can get worn out or damaged and those two brands are the ones it’s easy to find replacement parts for.
All of my junk is old. Dad gave me an old Sears Craftsman set he had, that was my first torch set. Still works great but parts are getting hard to come by. It has the convertible torch so you can use it for cutting or welding with acetylene. My big torch set is set up for cutting only, forget the brand of the torch but the regulators are old AirCo that I had rebuilt years ago. Make sure you shut the tanks off, crack the valves on the torch to bleed off pressure, then back the adjusters off on the regulators when you are done with the torch, keeps the diaphragms from getting worn out that way.
For just heating and cutting you can use propane and oxygen (or I’ve even seen shops run compressed air if they have a big enough compressor). For welding you have to use acetylene and oxygen though.