Maybe you can start with these first and see?
Costco - LED Motion Sensing Outdoor Spot Light 5-pack
or you can go the Second Route like I did for my Storage Shed:
1. Get the 45W Harborfreight Solar Kit ( Make sure to check their Flyers or Instore, there is a Coupon you can get the Kit for $149 - $159 )
Solar Panel Kit - Save on this 45 Watt Solar Panel Kit
2. Get a Maintenance Free Battery or you can use your old Lawn Tractor Battery or a Snowmobile Battery at Walmart. 35ah would be good.
or ebay:
U1 12V 35Ah Sealed Lead Acid SLA Battery | eBay
3. Get a DC 12V 8A PIR Motion Sensor Switch
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
4. Maybe you can add a Top Window on the Roof for Natural Lights. Search around see if anyone getting rid of their old Windows cause all you need is the glass and you can make your own frame out of 2x4 treated wood, I find tons on CL for Free. Use the Sticky Roof / Chimney Rubber Flashing to Sealed around the Window, it's Cheap and Rain Proof.
PS. If you decided to go with the 45W Kit, it's best to put Diode in the Solar Panel. 1 for Each Panel. I didn't do that to mine when the Cloud hit it, the Power transfered to the other Panels instead going to the Battery. This is a must !!!
10pcs 10A10 10A 1000V 1KV Axial Rectifiers R-6 | eBay
The Kit came with everything but the Battery and the Diodes, the 2 lights work great and if they burnt out don't throw it away you can reuse it see the thread below I started. So far it's working Great for me, the Battery always charging / full and since I rarely out there now, I think it's wasting energy, LOL. I have 4 Kits around my property.
See this thread;
http://www.tractorbynet.com/forums/projects/231040-solar-charging-help.html