How do I upgrade light duty (Bundera) axles to hold 37"

[MKarmyshev]

I mean at least 37s. I'm not talking extremely agressive tyres like Boggers, but something like 37" Mudzilla or 38" TSL. 39.5" Irok would be nice for extra flotation in the snow though
At this time I do not want to switch to 80 or Patrol axles for the following reasons:
1) loss of clearance because of huge diff pumpkin
2) they usually have 4.1 gears, so I'd have to regear them and that's about 1400USD in parts only
3) they are wide and heavy

As far as I could find out I need to upgrade Birfields, front inner axleshafts and rear axleshafts.

Because aftermarket parts like Longfields are very rare and expensive there ( I do not know even a single person who runs Longfields there, because prices need to be multiplied by 2 against what's seen on http://www.longfieldsuperaxles.com/ ) I wonder if it's possible to adapt stronger CVs from Patrol or 80 series Cruisers?

What has to be done with semi-floating rear axle? Will trussing help to reduce axleshaft bending and associated failures or I need to convert it to full floater (how?)?

Thanks in advance!