These HDPE (High Density Polyethylene) tanks from Speidel are a great choice for both fermentation and storage of your small lots, up to about 30 gallons. The heavy duty containers are much thicker than traditional plastic carboys and have a host of unique features which really improve usability. Among these features are the oversized top opening which makes them easy to clean by hand, included spigot which eliminates the need to siphon and the integrated handles which make moving these around a snap, even when full.
Like the traditional plastic carboys, these will not shatter if dropped - even when full. The high density construction is highly resistant to oxygen ingress, making these suitable for long term aging of wines up to 12 months.
Tip: Because there is going to be a small amount of oxygen contact, it is a good idea to adjust your SO2 measurement schedule to be more along the lines of what you would use with a barrel - every 5-6 weeks rather than every 8-10.