background picture for workbench3.1

[amiga4001]

I am setting up an amige1200.
It has internalcdrom,harddisk,delfinaflipper and a 030 Tcard.
I installed workbench3.1 as I think it's less demanding on the cpu.
Installed Newicons V3 and gotta sort that out as some drawers are not being changed into new.
But I also want a nice background picture on the workbench.
A .iff file I think with not too much colours like a 2 stupid dogs background great pictures with not too much colours.
What program is best for my setup to display the pictures?

[amiga4001]

I forgot it has this standard in the workbench.
Don't need any external proggie for this.
But how about a iconbar?
Is toolmanager the easiest way to go?
I just want something like amidock.
Or is this free and working with os 3.1?