The nice thing about custom Mando's is that they are just that: custom. Do what you want to do, and if it looks like you're straying from the Mando idea, we will let you know. 
I'm sure there are Mando's who like rocking the old school neo-crusader helmet but wanted the more modern body armor or whatever one you liked best. Besides, you can modify it! You've got creative freedom. Don't be afraid to try things. When it comes to custom Mandos (for the most part) nothing is set in stone. And like TripleD said. feel free to ask questions and have fun with what you're doing! Also, I would encourage you to look around at other threads, both here and on the Mercs site. I've learned a lot myself by looking at other peoples work and I'm only on my first set of armor. As for my character's name, Ordeyn, it's completely out of the blue. Lot's of people like to use Mando'a (the Mandalorian language) words as their names. There's a whole dictionary of Mando'a here: newmando
Hope that's helpful and I'm looking forward to seeing what you come up with!
