Caterpillar has partnered with Mitsubishi to make forklifts, but both have kept their brands separate for now. There are still specific models made by Caterpillar. They call them "Cat Lift Trucks" instead of forklifts officially, but it's the same thing.
Caterpillar makes forklifts with a pretty wide variety of capacity - anywhere from 2,000 pounds to around 33,000. They separate their brands by what powers the engine, selling both gas-based forklifts and electric forklifts.
The gas based ones can go a little faster. There are literally dozens of different models so you can get pretty close to exactly what you want, but Caterpillar's high-end gas forklifts can go about 20 mph. The lower end ones do 12-14. If you want to go with electric, it will be cheaper, but also slower. They generally range from about 7 mph to 10 mph.
Another good innovation Caterpillar has is the narrow aisle electric forklift. They're slow and have low lifting capacity, but they are squished in so that they can fit down narrower aisles in warehouses and they need much less room to maneuver. That's a big plus if your main concern is saving space as compared to speed.
