One of my booster pedals is for sale on the Doctor Tweek guitar shop website: (http://www.doctortweek.co.uk/shop/article_548/SJ-Audio-Boost.html?shop_param=cid%3D58%26aid%3D548%26)
The SJ Audio Devices Booster is a true bypass booster pedal that can help you stand out in a mix for use in solos, and can also be used to push a valve amp into natural overdrive. The booster has a high input impedance, low output impedance, and a flat frequency response, giving the pedal a clear and sparkly tone. The pedal is handmade using high quality components in Doncaster, South Yorkshire.
Doctor Tweek is a great shop and is worth checking out if you need some guitar effect parts (or even a boutique pedal or two 😉 ).

SJ Audio Booster Guts