Denise I think you could go blonde. As a naturally dark blonde who has been colouring her hair since she was about 18, do you mind if I just make a few suggestions? And you have probably already considered these but just in case...
Consider the use of bleach very carefully. It can be SO damaging. It is not so bad for those girls with short hair who have it cut regularly but with longer hair, it does seem to require much more TLC.
I don't think I would suggest a block colour. Your colour is so gorgeous, I think I would be inclined to do a half or even quarter head of a blonde that will work beautifully against your natural colour.
I had my hair coloured just before Christmas and we put more of my natural colour back in and lessened the amount of blonde foils. My hair has much more body and the colour (to my eye anyway) seems a little more natural.
Having said all this, I do like drama and extremes so I think going blonde would look amazing, but just not at the expense of damaging your hair.
Of all of these I like #3. It has warmth and I think the warmer tones will blend more with your natural color and be flattering on your skin tone.
Good luck.