Using heat to cook (mock) ceviche Although I love ceviche I'm worried about possible health issues caused by eating raw fish. 

I know that freezing it at -20° C for at least 24 hours would be effective against Anisakiasis and reduce (but not eliminate) Salmonella. I'm also aware that the whole thing of "ceviche's cooked by the juice" is just a myth. Raw fish remains a risk. 

Since ceviche's fish get de-naturated anyway by the lime (or other citrus), would the fish change considerably if I cook it at 60° C for some time?

What's the minimum amount of cooking time that would make the dish safe? Could this produce acceptable results? What fish would be the most appropriate here (that is, for being safe and tasty)?
The problem I see with cooking fish to dress as ceviche is achieving the texture.  Citrus juice firms the raw fish while baking, for example, will produce either tender, fall apart fish or dry overcooked fish.  Possibly bay scallops may survive in this substitution but I don't think so.  The reason I make or purchase ceviche is for the fresh, clean taste.  Not fishy.  Another suggestion would be using surimi which is already prepared to have a nice texture.  In the US it is called imitation crab or lobster usually made from pollack.  Just one final comment.  Consider the long history of this dish, and it goes back to before refrigeration.  It's unlikely there is any grave danger from using this process.  Buy a fresh, cold water fish, dice it, add the ingredients that you like, wait the required time and enjoy.  Relax!  Otherwise see www.trans-ocean.com for one surimi source.