Here is the Nankai Namba Station English-language information page.
http://www.nankai.co.jp/global/engli...mba/index.html
The PDF map indicates that there are elevators in the station. I've taken the Nankai Airport Express, and I reached the train platform by escalator, but the station boasts about all sorts of "barrier free" features.
Boarding the train is no problem. The floors of the trains are level with the floors of the station.
If you're staying in the Namba area, your hotel may have even more details to share.