what type of clips have i to use to hold the fuel line in place, will the plastic ones pass iva

Yep. As long as its secure. Can be p clips or push/snap on ones.
I dont believe there is a specified spacing, bit elec loom is spec as 300mm max, so work to that.

I bought 15mm rubber lined p clips and put both the brake and fuel line on the same clip. I modified each clip by putting in two pipe off cuts and tapping the middle to make each clip into an M shape, keeping both pipes apart.