I called InlinePro and they said it doesn't matter which block is chosen.

They're making 560whp on a complete stock S2000 engine with a cast log manifold and GT35R. They're working on a turbular manifold to be able to fit a GT40R in there.

Edit: They use AEBS sleeves, same warranty as the other guys in the market. 2 week turn around, and will offer a core exchange if they have one in stock at the time of sleeving.