I love Bronco too :)
We don't get high temps but 'Limelight' always does well for me, and glows in it's green way, and 'Hayling' has the most beautiful colour and form along with the waxy type leaves. I hope I get plenty more chicks from my 2 hens this summer!
Try not to worry too much Paddy, Last spring I was convinced I'd lost over half my collection after a long wet winter, but they virtually all bounced back after a bit of TLC