I can’t answer your question, but in true Internet forum style I’ll give a long post on stuff you probably already know. 
First, off just do Lanzarote. Everything else will seem easy after that. 
I haven’t found a single source for determining which race I want to do, but the links the others have put up are a good start. Weather and courses, and to some degree the field, change from year to year so once you’ve narrowed it down it’s worth doing a bit more digging on those few.
If you’re a strong swimmer, favour the windy, sea starts. Unfortunately the rougher the sea swim the higher likelihood it will be shortened or cancelled so this can backfire. Weak swimmer, there’s that river current-assisted race in the States.
Mountainous bike will reduce the impact of drafters on the results, obviously a tougher ask for the heavier riders though.
Almost all the run routes are essentially flat, but if running is your strength and you want to place well it’s worth considering the few hilly run courses. Temperature and shade are worth looking into.
I use Coachcox to analyse the field at the races I want to do, you never know who will turn up but it’s a fair yardstick. If you’re looking to win, then all the other athletes in your category are doing the same thing, so courses that suit people like you will have people like you signing up - a bit of a catch 22