If you must splurge on an eyelash curler, make it the Shu Uemura or the Shiseido. I give you two options because they're both stellar in curling power and shape, but either one could fit your own eyeshape better and I have no way to know which would work for you.
I also recommend using a waterproof formula for mascara; I find it holds a curl for longer. Go for a formula that isn't glossy, that can "weigh down" your lashes.