Extended Silicone gun

Hi

.As a part of my project , im willing to creat an extended silicone gun and i have some general questions about this case

first of all ,how do i find a model of a telescopic pole if there is one ?and what is the best material to choose for making this part(the pole need to carry weight of up to 1.5 Kilos)

Second, the mechanism of the moving object will be a cog(which spins by the power of an engine ) and a serrated bar which are vertical to one another . i would like to know if there is any existing model like the one that i described

Thanks in advanced ,Tamir