Ask over on turbominis.co.uk, they'lll have more experience with 13" tyres etc.

Using a steel wheel or alloy makes no difference whatsoever.

But seeing as you're 4wd and relatively light, I really wouldnt be wasting huge sums of money of drag slicks. It really will make very little difference over a decent grippy tyre.

You will have no difficulty making superb 60ft times even on 888's etc and traction should not be a concern
And some drag slicks may require a burnout and some heat to actually work in the first place. So may actually be a backward step.

If they're available, something like a super soft hillclimb slick tyre would be a good compromise and work from stone cold.