I would advise against trying to recruit a crafter to perform a series of synths just to save you a few gil on an item that is readily available on the AH. With the saturation of high level crafters these days very few items are sold for unreasonable profit - or else they are quickly flooded back to the standard thin margins.
Plus, looking at the given craft levels on FFXIAH.com (83LC, 55CC), it would be a tier 0 synth for lvl 100 Leathercrafters - they would have to have their crafts specially aligned to conform to tier 1 on this. So you'd be looking at a ~1% HQ rate, assuming those levels are correct.
Odds are unless you find a crafter who is a friend, they won't be keen on cranking out a bunch of synths for your benefit. I'm happy to help out strangers on synths that aren't commonly found on the AH (say, a pair of rarely requested cursed pumps or something), but I'm hardly motivated to help someone get an HQ that they can simply pick up from Whitegate.