Hey sis! Congrats on your decision to do a waterbirth. I have done an unassisted water birth and plan to repeat again. It was wonderful. You don't have to use a birthing pool but if you can find a family pool that is deep enough so that the baby doesn't surface before he/she is ready to be pulled from the water, you will be okay. You know how people hook those hoses up to their bathtub faucet to give thier dogs a bath? I would just use one of those to fill the birthing pool or use your bathtub (although it will be less comfortable and give you limited mobility.
My midwifery has tubs for home births that they give to moms to use. I would check with your midwife first to see if they have their own for your use.
My midwife also does a tub rental. Chances are if they are trained in water birth, they'll know where to get a tub.