120w 13 cm Amplifier by W6PQL 2304 is one of those bands where you can find some surplus components to build with. This amplifier uses two 60w Spectrian amplifier boards with the usual input and output hybrid coupler and combiner. http://www.w6pql.com/120w_13_cm_amplifier.htm
A 13cm Power Amplifier by G6TVJ Having built a simple synthesised 13cm ATV exciter my thoughts turned to what could be used as a power amplifier. The exciter produces about 10mW perhaps enough to drive some sort of MMIC or hybrid amplifier. http://www.cqham.ru/projects/13cmpa/13cmspa.html