I’d say the PS4 pad is probably a good bet. I know quite a few players who use it and like it so long as it’s in good condition. I’ve not heard much about the XB1 pad, and I’ve heard the HORI pad tends to wear out fairly quickly.
In general, d-pads are better than using the analog stick, since it affords greater precision in your inputs as well as greater speed (compare doing forward-forward with pad vs analog). If you don’t have some mean thumb calluses, then get ready to deal with some pain until you can build them up. I remember doing training mode back in the day until my skin was raw and the top layer started coming off. Not a problem anymore.
If you ever decide to go all out and purchase an arcade stick, get a good one. Almost anything that’s new and in the sub-$100 range for arcade sticks is nearly unusable garbage and will make learning stick much more difficult than it would be otherwise.
Tips: Learn to use the pad in the way most comfortable for you. Different players use different parts of their fingers/thumbs to manipulate the controls. Generally though, the people I see who use the middle joint of their thumb rather than the thumb tip for the d-pad tend to have a hard time doing motions. If you don’t have much experience using a pad, play other games with it too like some classic arcade games. Your hands should get used to the usage of the pad and the placement of the buttons.