Split rims to Sun raiserers?????

Can't help myself with this one.

Daryl from your post I take it that your major concern is the Coopers posibly throwing up rocks for a half hour after you have left the gravel and brought your rig up to 'cruise speed' on the bitumen.

This may happen, however I would have to see it to believe it, and whats more the first half hour on the bitumen is going to be sheer bliss compared to the previous half hours (many of) spent on the grave.

As to the right choice - well any choice you make is 'right for you'.

I don't think there is any one brave enough to put his/her head on the 'chopping block' and do the tyre recomendation thing.

Its a personal choice for a personal situation.

Bit like buying 'jocks' - you know , size, style, colour, weight, wedgie proofing, comfy factor - all personal preferences to fit, accomodate, compliment your bitz.

Same with tyres and you rig set up.

Mate I don't know that there is too much consensus regarding Coopers being a "really good tyre". Do a search and you'll see what I mean. It's very much a love em or hate situation.
Odd that you are changing your vehicle tyres to match the trailer - cheaper the other way around since less tyres to change.
The only tyres I've had which didn't collect too many stones were the mud terrains. But when they did pick up a stone it was a big sucker. So if the stones annoy you, you're out of luck because I suspect that all tyres will do it. I have yet to find one that doesn't.