Need advice on buying Lorica Segmentata metal and leather

[sillious saurus]

I apologize for the double post, I wasnt sure if anyone would see this posted to a previous thread from a few weeks ago so I made new one. Anyhoo, I want to buy the leather and metal for my homemade seggy today. Now I found leather and they have 3-5oz belly, or 5-7oz belly for a good price. Which should I get? Is it better to be a little thick or thin? As for the metal, I found a place that has 18 gauge for a reasonable price and will do some of the cutting. This is where I need help--are there generic lengths I should shoot for so I only have to cut widths. I wouldnt need exact meausrements specs for myself to that end if they are just doing lengths right? Thoughts?