I completely agree, we were planning a flanders red or lambic for the second use.
Flanders Red for the first batch, unless the previous beer was something that doesn't leave too much character in the barrel. Lambic or American Sour for subsequent batches, since the bugs from the Flanders Red will get into the wood.
If you decide not to do a Flanders Red for the first batch, I think you'd need a relatively strong amber or brown beer - without too much hop or dark roast - to stand up to the barrel character. You can always do test batches and doctor them with whatever wine the barrel originally contained to get a sense of what the combined effects will be like.
Whatever you do, however, get moving quickly. There's a lot of air and a lot of alcohol in that cask, and the air is full of acetobacteria looking to move in and set up shop.