I'm designing a remote control based on a TWS-DS-6 433.92MHz transmitter and I wanted it to be really compact and energy efficient.

I plan to have an Attiny85 controlling the transmitter and use VitualWire software library to send data to the corresponding receiver (which is already up and running). I'll have the Attiny85 sleep most of the time, only waking it up when the user presses one of four buttons on the control. I'll power the transmitter using a uC digital output pin so I only turn the transmitter on when I need it.

The transmitter input voltage is 5V. The controller will have 4 push buttons, each of which will send a different command to the receiver. I plan on mounting the transmitter boards on one of those small remote garage door opener cases like the one below.

I have a version of the transmitter working on a Arduino Uno with an Atmega328 (not on deep sleep mode yet) on a protoboard.

Could someone please help me choose a low quiescent current 5V regulator and battery for my remote control?

Also, does anyone see any flaws or room for improvement on my design?