Use the ‘Button’ or 'Button Link' element. Widen the padding to your liking, also the text on the buttons can be changed in size, colour or font.
For the image buttons, give them an image background. The images here have been resized from originally fairly large to just a 200px width and made to cover.
As for the gradient buttons, they can have a background colour with a partly translucent gradient on top of it. It is also possible to use an image with a gradient layer on top.