Welcome. Your in the right spot.
First contact FBJ, (firebladejedi) he is the det armor expert.
Then start looking around the forums on information, pictures and builds from members blazing your new found trail.
Then decide on budget, skill and time.
In time you will tell the difference between them all. Welcome to the obsession.
Remember... The golden rule of props.
1. Cheap (I use this term loosely)
2. Accurate
3. Fast
You will only be able to achieve two outta three. (at least for now) Never all at once. Its like a Tattoo. Cheap ones are not good, and good ones are not cheap. Its not just the armor, money gets poured in with accessory and build supplies.
Next contact your local garrison. Good stop as well.
Then its suiting up, and getting active. Nothing feels like a great costume in public. Shock and Awe. Rock on man. Welcome.