i do alot of trout fishing ( i live in san diego) and i would get it from a hatchery cuase trout normally die after getting caught, one hatchery thats a possibility is mount whitney when i went fishing in the sierra mountains we stopped there and looked around they have a paper that says how much it is to buy trout i dont remember but i thought it was like $25 for a family of rainbow trout, by the way what type of trout do you plan to get? but whitney feeds their trout some type of pellets. hope this helps!
I know what you're saying though. Larger trout seem to take it harder than juveniles. Big thing for a successful release is making sure you hold them in the water long enough for them to recover from the fight. If you just toss them back in the water after struggling on the line for a couple minutes, they are often going to go belly up from exhaustion. Hold them right-side up in the water for a couple minutes and move them back and forth to keep water flowing over the gills and they will usually recover and swim off on their own before long.