Merv
Don't be confused, there is only one true engine
but I'm guessing a lot of the blokes have gone dark side because of "the Force"
(read legislation - not Darth). Where if the reasonable choice had been available they may have stayed with the more traditional donor source. By reasonable I also mean the more easily fitted smaller Windsor over the newer modular Boss.
Think back to what the Ford V8 supercars could do with the mighty Windsor, so you can get the neddies from the motor if you have the desire.
Bang for your buck, I tend to agree the Chebby beer cans seem to offer it, but staying with the expected heritage, then a Ford engine it can only be!
As to choice you need to hit an AU series sourced engine. The last of the AU series was the stroker variant, not sure if they were known as AUIII or TE50, as I've seen AUIII's advertised with the 220kW motors. But the strokers are very nice 347ci if you can find one but they are in demand and are holding price.
Not sure whether the whole range would be acceptable for compliance, the AU started in 2000 I believe, but you should be able to get a cheaper early motor for starters. You may even be able to regress further as Craig suggests but you need your engineer's advice on this!
For example on ebay at present is a half cut 2001 series ute with manual T5 gearbox and supporting bits for $5,500, a 200kW tickford motor only with all the bits for $2,500 and a Ford racing crate motor for $6K needing the EFI but brand new. Not sure what's on the ford forum and of course the wreckers so there are numerous sources.
I'm now forced into a part rebuild of my 220kW and I am reliably told that a good set of aftermarket heads and mild cam will let my 5L - 302 achieve 220 -240 kW at the rear wheels. To me that's a damn good start for the uninitiated.
At the end of the day its your car your choice but lean the way you know you will be comfortable in the long haul and then you wont regret the choice.
Happy hunting!