Hi there and welcome to the mercs.
Great to hear you have some thoughts on how you want your kit to look. make sure and head across to the
Jadd Halls of Knowledge, there you will find lots of guides and tutorials on anything from armour, weathering, electronics and much more.
Helmet wise, I think you have been fortunate not to have purchased one of the others, I don't see any issue with this one.
First things first, you are in the right place for us folks to help you build you kit.
Post plenty of pictures so we can help you with armour sizing, positioning and attachment.
Look forward to see your progress