Outer Limits 4x4 Board

Gday all how are you going? I've just recently picked me self up and 1983 toyota Hilux LN46 off a mate, its sat around the shed for the last few years and only gets started every now and then. Its got 194,000km on it. I've been taking it off road abit and have seemed to have got the bug. But the old girl with a 2.2 and 4 speed doesnt seem to have enough go to push the bigger tyres and get places most others do. I have a few Questions and all advice would be greatly appreciated.

I am looking at putting a 5 speed in her, from what i have read i need to get a G52? How full on is the installation and does anyone know of some places in QLD that could help supply me with one?

How do you convert a 4 speed into a 5 speed? what parts are involved and is it worth it?

Would there be any benifit turboing the 2.2 that in it now?

Motor options are: 2.8L or 3L and turboed, has anyone done this conversion?

Any other consersion ideas will be taken into consideration.

Thanks again.
Nic

Just need to change the whole gearbox. Easy as job.
Wouldnt bother playing with the 2.2, they are a dinosaur and parts are hard to come by.
I would go with the 5L (3.0L) turbo'd.