ok, im on getpinz.com and i want to order 18 g (dont know if they have it) and 23 g at 1.5" .. ok with these syringes can i remove one needle ( 18g) and replace it with the 23 g needle? I should have asked this sooner, but never thought to post it up.. also if they do not have 18 g, do you of a place that sells 18 g? thanks a lot guys!