The Walkabout is a remarkable head. I used one for years with a number of cabs. I'd try different cabs first.
If you find you want something in a similar ballpark but with more present mids and more headroom, I recommend the Handbox R-400 - IMO it's a 'Walkabout Plus'.
Hello! Either email Leszek at [email protected], or message him on Facebook. The latter will probably get a quicker response. The output is - IME - loud. It’ll be poky as owt through a fridge...