a 289 can be registered with no engineering hassles
Fuel injection is easier to implement
more space in the engine bay
Probably easier to get a s/h cleveland in reasonable order
4 Barrel manifolds on XCs as standard
351s more plentiful than the windsor one and most parts are interchangeable between 302 / 351.
Since XWs and XYs ran both motors the hardware to fit them is interchangeable, It comes down to personal preference and the flavour of the beast you are building.
If I was going to build an XT ute from Scratch that I wanted to be economical and reliable Id look very closely at using a fuel injected windsor and box out of an XR8. I'd be looking at about $5k short term but I'd have an engine with a reasonable life before I had to rebuild it and a five speed.
As it happened I had a Cleveland and 5 speed lying around from my last ute so that formed the basis of a drivetrain. I reckon you could get a Clevo and single rail in good order for less than $1000 so you would have a workable setup for less upfront investment that is simple to work on with no electronics or fuel injection but you would miss out on the economy and "turn the key and it just goes" features of the injected engine.
If I wanted to go for the resto I would use an old windsor for originality. If you can find an old windsor in good nick it would cost you about the same as the clevo although it won't go as hard stock.
If you have big bucks to spend on an engine its a different ballgame again and you would do well to look at what you want to do with the vehicle ie drags or a streeter and make a decision after talking to people involved in those areas.
Hope this helps