[Baron Munchausen]

There is always the diplomacy option, if you have contact with any other empires. Is there anyone you could form an alliance with? A 'second front' can sure be helpful in a war with a superior foe. Trading technologies effectively doubles up both of your research abilities.

As far as other research areas, have you got an bio-weapons? Especially if this is something you don't usually use, it could be a surprise and he might not have medical technology. All you need to do is get ONE hit on a planet, too. Not destroy it. If you can get at least level 3 plague bombs and catch him flat footed, you could do a LOT of damage.