A star bit with hole in middle, or star screwdriver with hole, or star bit with hole is called a Security Torx. I found a few good sets for you. These sets have all the common sizes and most are warranted for life. Click on the Colored/Underlined words to buy from Sears.com
1/4 inch HEX Security Torx Sets. These bits can be used in you cordless screwdriver or impact driver.
Basic set. Craftsman 6 pc. Bit Set, Torx Security
All the Common Bits in One Package. Craftsman Professional 51-pc. Magnetic Driver with Bit Sets
Very High Quality Set. Wiha 79447 X-Selector Bit Set with Tamper Resistant Torx Bits and Quick Release Holder
Triwing: 1, 2, 3, 4. Torq: 6, 8, 10. Spanner: 4, 6, 8, 10. Tamper-resistant hex sizes: 5/64, 3/32, 7/64, 1/8, 9/64, 5/32. Slotted: 6.5 and 8mm. Phillips: 1, 2. Pozidriv: 0, 1, 2, 3. Square: 1, 2, 3.
Socket Sets. These sets use your existing 1/4, 3/8, and 1/2 inch drive ratchets and extensions. Buy both sets to have all the sizes.
Craftsman 7 pc. Tamper-Proof Torx Bit Socket Set
Craftsman 5 pc. Tamper-Proof Torx Bit Socket Set