Hmm orangey reds....that's a toughie.
Maybe check out Coppering that is a beautiful coppery orange. Peppier is an orangey/coral shade. You could possibly blend it with Full Flame (a pinky red)
I see you said you are in the UK. If you are shopping in London go to the Pro store which has a bigger choice, check out Ruby Red pigment, Pink Bronze pigment, and Electric Coral.
The pro store also has a pan eyeshadow called Red brick which has a description of orange red but it doesn't state the finish of it.
If you aren't going to the pro store you can still buy Pro products via MAC mail order which is based at the Pro store.
Also check out E-bay for pigment samples especially US sellers as they are so much cheaper. Pick up samples of Copper Sparkle, Pink Bronze, Ruby Red and Electric coral.