I'll create one large infographics banner for your service with adobe illustrator.
Maximum Width 2500px, Height 7500px
Width to Height ratio is 1:3
e.g. if you want a infographics of width 1000px, then height will be 3000px.
See the service infographics banner made by me.
You have to provide text for the service infographics banner. Also images you want to add.