Put mixed gelcoat in plastic food bag, squeeze it in one corner, twist bag around so you end up with all gelocoat trapped in one corner and then just nipp off tge corner (much like if you are baking cakes) and you will be able to apply nice lines quickly without any mess
For layup you can go as low as one 200g cf followed by 200 cf/kevlar hybrid as there is enough geometry on your side(extra 400g on the mounting points)..... for street car i normally go with 1mm in total for fenders.