May I join this thread, please, as it's something I'd quite like to know, too.

There are quite a few varieties, but you can whittle those down somewhat by deciding a few things - first, what colour berries do you want, second, how big in terms of height and spread do you want it to be ultimately, and third, do you want a variety that's scab and fireblight resistant. That narrows the field considerably. Also, don't forget there's a variegated form (I particularly like this one) but it grows more slowly than the green ones, and only reaches 6 feet.

I have 3 Pyracanthas....Orange glow.(orange berries).Coccinea (red berries),and Soleil d' or (yellow berries ) ..all are good in any positions..very hardy,and strong growers..ideal against a fence..all mine are against an east facing wall..and flower and berry profusely...good background shrubs...need to be planted a good 12"away,as they dry out,with being in a rain shadow...so need watering well..also they can all be pruned and trimmed,if they get too big.. hope this helps, Ojib and Gattina ...

Thankyou, Bloomer and Bamboo. That was really helpful.

Would I be correct, Bamboo, in thinking that the variegated variety might not be quite as hardy for here? And, to give more info, I would like the plant to go to 6ft eventually but the spread is not a problem - there's a lot of bare fence to cover!

Bloomer, I have looked at all three of those you suggested and in fact any one of these would suit, thankyou - or perhaps all three! Do the birds eat the berries and if they do, do they have a preference? That would also help me choose.

Thank you from me, too!

Glad it helped you both...The birds do eat the berries,but
I find the yellow and red ones were the last to go..and only when it is really severe weather,and there is no other food..mainly the blackbirds here..in fact,there are still some shrivelled ones on the red one,so they mustn't have been that hungry this winter..plenty for all,anyway..:o)

If you want berries the birds will eat, don't choose Pyracantha mojave varieties - they avoid the berries on that one.
Generally speaking, variegated plants are sometimes less hardy than their plain cousins, and often less vigorous, but in this case, the one to avoid because it is both those things is P. 'Sparkler', which is not reliably hardy. P. 'Harlequin' though, is hardy, but much slower growing, making 3 x 3 feet after 5 years, ultimately 6 x 6 feet.
If I wanted a taller one that wasn't variegated, I'd probably choose P. 'Orange Glow', mostly for its orangey/red berries.

This has been very helpful, thankyou again Bamboo and Bloomer.