Trip Hazard recommends the use of Energizer batteries for your pedal.
There are other good brands out there, and you are welcome to try them all. However, many batteries these days have a plastic sleeve around the body that makes them too thick to fit into the clip on the PCB. So a slim, metal battery is what you'll want.
We use full-sized, double-sided, plated-through circuit boards to which the stomp switch and pots attach from the back side. Pots are the same Bourns plastic conductive models used in XQP modules. The stomp switch is a 3PDT full bypass, and an LED indicates when the effect is engaged.
The remaining parts are visible from the board's front side when the bottom lid is removed (Technically, the PCB sits upsidedown). The battery clips in very solidly onto the PCB itself. The power jack is attached directly to the PCB, and the input and output jacks are wired to the board with shrink tubing around the jack connectors to prevent shorts agains the enclosure. All parts are of the highest quality.
And speaking of shorts, Penney's is running a sale. No, we have taken a couple of steps to help prevent explosions. First, the power jack is closed-circuit, so it switches the + voltage rail from the battery to itself when a power plug is inserted. Second, a diode protects against reversed voltage caused by power supplies of the wrong polarity. Trip Hazard pedals use the standard center pin-negative 2.1/5.5mm power plug arrangement. Power supplies are available from many suppliers including Trip Hazard.
The input jack is a Switchcraft 13 which switches the power on through an isolated switch when a cable is plugged into it.