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Gunnar, Adley, and Jackson - based on the limits of the OP choices, but I understand wanting to keep Burnes around.
On the G-Rod mentions, not a bad idea. O's have control, but if he continues to be a frontline starter, an extension could be cheaper than the last 2-3 arbitration years.
Of those 4, it's Gunnar #1 by a large margin imo. Then Holliday, forward closely by Adley with Burnes a very distant 4th, unless he's willing to do a 3 or 4 year contract. I really don't want to sign Adley for more than a couple of his FA years, and I'm not sure he goes for that.