After you get the dragon armour it can be 'upgraded' by having Grisha forge the dragon gem into it. The stats will change (potentially but not necessarily better), but if you wish you can buy back the original armour and only use the forged version to complete the dragon armour quest (wearing the full set once).
If you are not having problems taking a lot of damage I wouldn't reload a huge number of times. Generally I got close to the best stats within the first few loads. Just remember to move the armour in your inventory before saving good candidates. The properties of items placed directly in your inventory are not set when you identify them, but need to be moved. I got a very nice ring in Verdistis from the soldier I healed in Aleroth, saved and then reloaded to see if I could get anything better. After a couple tries I gave up and reloaded the first version, only to find the stats were not set; I had to reload for an hour to get a ring comparable to the first one.
