Waiting until Chapter 5 is the most likely hedge you get. Split Infinity's Chocobo Ranch Guide includes a handy table showing the percentages per demeanor and area (search key: G0611).
It's a crapshoot. Fill up and go poll the birds in the stables to see their maximum level. (In earlier chapters, you could use save-raise-reset test cycles.) Release any that won't measure up and go harvest another batch.
If you're getting crap, reset your game or console to shuffle the odds. Worth a shot with anything that even remotely seems random — rule o' thumb with any Square game, for that matter. --- Guides and other contributions: http://www.esque.com/slr/gamefaqs/ FFX, FFXII, KH, KH Re:CoM, KH2, Okage: Shadow King, Secret Agent Clank
Just keep sending chocobos. Needn't be a Lv.5 bird to find the fiend colony. Last time, I'd sent a Lv.4 bird and it found it after a couple of tries. Save before you check on its return, then reset until the dungeon is found. It's really that random.
Also sent a Lv.3 timid to Bikanel at the end of Ch.3 last time and that was plenty to open up the Central dig site, even before returning to Clasko. (And then I reset until that bird returned okay; running away is not a given.)
Now, the chocobo dungeon itself is another matter. Repeated random attempts can heighten the frustration, so it might be best to forget whatever you've tried and take it methodically. Gather four birds with Lv.5 potential, and dispatch the group at Lv.1 to Calm Lands. When they return, level all four at once, but only once. Feed them to full health, then send them again. Repeat, for all five levels.
Temper doesn't matter, BTW. Last time for Calm Lands I used a timid, a normal, and two bolds, with four Lv.4-5 birds on reserve. --- Guides and other contributions: http://www.esque.com/slr/gamefaqs/ FFX, FFXII, KH, KH Re:CoM, KH2, Okage: Shadow King, Secret Agent Clank