D. baronii, and onilahensis would certainly be tops on my list. They're easy where you are, and variable enough to be interesting. They will eventually get to be tall bamboo-like stems about 20 feet tall, so you might want to leave room to plant other, shorter things nearby. D. psammophila would also work, as would D. lutescens. All are clumpers.
Euterpe's a little tender for the full sun. They're better, in my experience, in semi-shade. Plus, it's a single-trunker and I think you'd be better off with clumpers.