Rule of thumb is add room dimensions together for size of chandelier. 27" Go with smaller version. Also chandelier should be 1/2 to 2/3 width of table. Hang so that bottom of fixture is 30-34" off table surface.

How large is your table? It's more important to size the chandelier to the table, not the room itself. The chandelier should be 20-24" smaller than the width of the table. So, the 25" diameter chandelier will look best over a 45-49" wide table, which is likely what you have. But if your table is wider, then you might be able to go up to the 34" fixture. Hang 33-34" above the table to accommodate the ceiling height. 30" for an 8' ceiling, add 3-4" for each additional foot of ceiling. Or, if one is very tall (over 6'), I like to hang the chandelier a little higher so the "view" is better.