If your goal is just to get the car running for a year before swapping a V8, I'd recommend keeping it as cheap and simple as possible. Otherwise, it's just flushing $$$ down the toilet.
Use interchangeable parts- like a good electronic ignition module. Most aftermarket ones work on 6 and 8 cylinder engines. Getting a wrecking yard (or even rebuilt) DSII dizzy isn't that much. Coil and module will both work on your 8 later.
If you have porting equipment, do some basic porting to your head. Don't pay a lot to have it done, though. Getting a big valve head from a later year 6 from a wrecking yard will help motor breathing if you can find one cheap.
Headers are a nice thing, but are spendy for a 1-year engine.
Buying the Ford Falcon 6 Perfomance Handbook (links available from the FordSix main page) will give you a lot of tips on tweaking the basic motor without spraining the pocketbook.
A T-5 swap makes it more fun to drive. The trans, if taken from a V-8 car will bolt up to your new 8. A 4-cyl trans won't handle the torque from an 8. The bell housing adapter plate and (maybe) trans crossmember will be money gone.
There's certainly more ideas, but that's the line of thought I'd take on my shallow pockets.
Hope this helps,
--mikey