I have started using the Renegade brand of tools from
Trade Tools. The ones I have are 10.8v Li-ion powered - currently I have the drill, the circular saw, the jigsaw, the LED torch and the
multitool which is an amazingly useful piece of kit.
I wondered whether a 10.8v tool would have enough power, but so far they have done everything I wanted (except I tried the circular saw on too thick a piece of timber and it stalled). These tools are very well made - I first discovered them when the carpenter who was working in our house left his multitool behind and I tried it out before reurning it to him!
After you have your first tool and a couple of batteries with charger, the rest of the tools are about $78 each.
Trade Tools is a great place to buy all your tools - they sell most major brands as well as their own brands which are incredibly good value.