Thank you for the warm welcome! This is actually my first 'Official' prop project ever, before this it didn't exceed much more then a paper helmets and pep busts. Foam is by far one of the best materials to work with, that I have come across.
As for the amount of tiles, estimates for my suit came to a total of 16 tiles, including 2 or 3 Oops-I-messed-up-tiles. This all depends on your body build of course, but 16 tiles will be plenty to complete a suit.
As for colour, if you are planning on painting your suit with a custom colour, go for tiles that come as close to that colour as possible. Might you contract bruises in your paint, it will be less noticeable. If you want to go for the original, pick a nice grey, it'll make the black accents of the suit stand out more. Like the pecks and spinal cord.
If you're feeling a little darker, go for black and make the accents shine by coating them with a thin layer of clear epoxy resin. For stripes I plan on using coloured vinyl sheets. Haven't tried that yet, but I'm confident I could work. It's a lot sharper then paint.. witch messed up one of my bicep pieces.
In a week or less I will publish my templates to the masses. This will include a codex with all the information I have accumulated so far, an info-graphic that tells you how to measure parts, and a guide on how to scale the templates. I will try to have it up as soon as possible but life is a busy hobby
Be sure to let me know where to find you WIP once you've started, I like watching other peoples work process on Mass Effect armour.