Avon and Peral,those are new to me.I may have heard of Avon,but both are not too common
Oneal is an older Southern Highbush variety that is suppose to be early and very good tasting.
Sweetheart is a new hybrid Northern/Southern cross and is said to bear two crops a year. Brady

Sweetheart does state it crops in the fall also but so does Emerald and the berries dont sweeten up in fall. I think its a good sales pitch though! Not saying it wont work cause I havent tried Sweetheart, just a little sketchy about fall blues. From what Ive read the zones havent been nailed down as to where it will thrive, at least the southern zones havent been nailed down. I also havent seen a chill hour recommendaiton on it either. Pearl sounds interesting after reading some descriptions of it. Oneal is supppost to be a great berry but doesnt produce a lot of fruit. If you dont like to thin fruit buds in the spring Oneal would be the way to go. Pretty much all the newer Southern High Bush over produce and do require bud thing. The only one Im aware of that doesnt is Sweetcrisp. If I had to choose from the varieties you stated I would have to get 2 and hope they flower close enough to each other to get good cross pollination and would choose Sweetheart and Pearl. There are alot of online nurseries that carry bunches of other varieties that are proven in your area. Maybe alittle research would give you better options, proven options.

I would diffenently look for early,mid,late ripening varieties so you have fruit for monthes..

Here is a link that might be useful: Blueberry