almost everything is possible with paitence, i think it takes good fibreglassing to make pillars but i know you can buy them for guages so mabey youll luck out and a tweeter will fit em, as for kick panels ive been lookin on cardomain.com as to how ppl do it, not too diffucult i think but it will take time, sorry i dont know more someone will help you out better
Lots of time, patience and skill goes into kick panels and about any good custom fibergalls job. However there are some very nice kick panels out that are prefab. May want to check out q-logic or some of the other prefab manufacturers. I will openly admit I have used them before and they work great. good luck