Hello Patrick
I think you could stretch a 1:22 figure, but only up to a point. For me, the governing things are the head and hands - if you stretch the body/limbs but keep the dimensions of the head/hands unchanged, it can look a bit odd. Bear in mind too that a tall person in 1:22 could quite easily pass for a short one in 1:19? e.g. 6ft 6ins in 1:22 is an 8.8cm high figure, which equates to 5ft 6ins in 1:19.
But having said all that, why not have a go? I would suggest chopping an existing figure to start with, as you have the basic body shape etc already there for you. If on the other hand you try and start with a wire armature and build from scratch, you'll also have the task of trying to build in the detail. I always found that very daunting. By way of a suggestion, get a figure, dismember it and rebuild with wire 'joints', adding, say, a millimetre gap between each joint.
Flattering though it is, I'm not sure a section all to myself is a good idea. I am not really a sculptor in the true sense - much as I would like to be, and all I am doing here is learning as I go, and sharing my experiences in the process. Personally, I'm more than happy to continue posting threads here, and thereby allow others to pass comment, ask questions etc. When you have a go at this yourself, you'll find that it really is as easy as I've said anyway!