2006 Impreza R Sport short engine needed - help?

Morning folks, following on from the piston slap debate and then the loss of power well it seems that I'm also losing compression on 3 so it's fair to say that I'm going to need a rebuild / rebore etc etc - silly money and the car isn't worth it so next best option is to find a short engine and have someone fit it on mates rates. I can sort out the latter but does anyone have a decent short motor for my 2006 Impreza R Sport manual saloon non-turbo? Obviously there needs to be no previous knocks, bangs, rattles or compression fails otherwise I'm chasing my tail, not to mention minimising further any chance of making it to the slopes this ski season !!! All help appreciated as ever - no point going down the diagnostic route further as I'm firmly up against the wall already, it's a short block replacement for sure. Thanks in advance folks - what a sad entry into Subaru ownership 😟