The Zoom units aren't great for this, the octave up effect has a noticeable delay and just didn't sound convincing.
I got much better results running a Mooer Tender Octaver (EHX POG clone) into a Joyo American Sound (Fender guitar amp sim). Mike Kerr runs a POG into a bunch of Fender guitar amps, so it works quite well!
You may be able to pick up a used Boss LS-2, TC Sub'n'Up Mini and Joyo American Sound for just over £100 all in.