What's your budget like? Any look you're going for or trying to avoid?
Because you've got quite a few options and in my opinion, they all look pretty great.
Finnex LED fixtures are nice and sleek. They're also cheap for that size tank. About $35 for a 12" FugeRay. (That would be my pick) If you ever decide to go low tech, you could raise the fixture a bit or just add some layers of fiberglass window screen between the tank and the fixture to lower your light levels.
WavePoint makes some cool fixtures that clamp to the back of the tank and are suspended above. You can remove pieces of the extension arm to get it just right for your tank. Price ranges from $40-$60 depending upon the fixture.
If you want to be really fancy (and spendy), there are PAR bulbs that you could use in conjunction with a gooseneck fixture. You could spend $100+ on the bulb and probably $25-$30 on the gooseneck. Not worth it in my opinion
Not interested in LED? That opens up the door for all kinds of options. Everything from a really nice desk lamp with screw-in daylight CFLs to Finnex or Fluval clamp lamps. If you went with a nice desk lamp and CFL, that'd be the cheapest option and would allow you to adjust your lighting levels with ease. You could raise or lower the fixture or use different sizes of bulbs to find just what you need.
I spent a bit of time at Target and Home Depot earlier. The modern desk lamps I thought were nice were all $30-50ish. So I think the Finnex may really be the best bang for the buck and it looks pretty nice on a tank.
Be sure to start a tank journal! It's always nice to see people document what they're able to do with tiny tanks and new things like LED fixtures.