See the attached link for some assistance. You might want to be aware that flowering cherries can be (and frequently are) prone to a host of disease and insect problems. Of your possibilities, I'd put 'Autumnalis' at the bottom of the list - I've yet to see one that looked the slightest bit robust and most look like they are at death's doorstep. Most retail garden centers in this area no longer offer them.

Yoshinos, Prunus x yedoensis, seem to be some of the most hearty (and hardy) for our damp spring climate, but flowers are white from pink-tinged buds. For pink flowers, Prunus serrulata 'Kanzan' is a consistent performer.

Here is a link that might be useful: flowering cherries in Vancouver BC

Yoshino and Akebono are beautiful and do well here. Look pretty much the same but they are white flowered, from pink buds, but best of all they're one of the first trees to bloom in spring, starting in March with the flowering plums but are much prettier than the plums. Spreading trees.

Kwanzan is the other most common one here in western WA, blooms much later, larger flowers, pink, and burgundy new foliage. The burgundy and pink clash to my eye and the colors are both a bit on the harsh side but I've learned to like them. Beautiful fall foliage color too, big spreading trees. Not pest free but do reasonably well and can live to a huge size in well drained soil.

Your sandy soil should drain well enough for cherries if there's no shallow hardpan beneath it but you'll need to add organic matter and fertilize yearly if it's nutrient poor, as sand can be expected to be.

Wow! That was all really helpful, esp. the photos. Will now have to see what I can find here on the Sunshine Coast. The Kanzan and the Shidare-Zakura sound good... hope I can find one of them. Thanks so much.

For more on this topic...

Here is a link that might be useful: Plant of the Month - April 2005 - Japanese Sato zakura in Seattle - Prunus cultivars.

For what I would get instead of a flowering cherry...

Here is a link that might be useful: Japanese Apricot - Trees Forum - GardenWeb