What type of yucca should I buy?

I love the look of yucca plants / trees and would like a couple of them in the garden at around 6 - 8 ft high. I have seen some with flowers on too, at least I think they were flowers. My question is, which type should I be shopping for? I am new to gardening and have been told that yucca will grow to 6 ft very quickly. Is thus true? This question may be better placed in the begginers section.

 

Hi Paterson, Is this the plant you mean.. If it is, its a Cordyline.. It Flowers and can grow way over 6-8ft..

 

I think if your looking for an easy yucca that can reach 6ft, probably yucca gloriosa would be best.

The variegated kinds are very good to look at while your waiting for them to flower.
I wouldn't call them fast growers, especially at first, but they can, given time, make a large clump, that needs a fair bit of space.

The sharp end spines are the main problem, if its in a place where there is likely to be people walking, as it can get a bit dangerous.

Filamentosa and flaccida flower well and have no sharp spines, but are unlikely to reach 6ft.

Or maybe your really after a Cordyline as YDD suggests above?