If you're getting a jack to use to change a flat tire most bottle jacks won't fit under the axle once the tire is flat, too tall. If jacking from the frame they're too short & require plenty of blocks. Plus they are heavy to move around & store.
But as mentioned get more than you'll need. Check out the ones at Harbor Freight, good selection of different sizes at reasonable prices.
Not trying to talk you out of buying one, just from my experiences.
Danny & Linda
Sold our '13 Thor Redwood 36 FB
Currently RV & truckless