That's the point , I would like to be adjustable. I cannot use preset currents. As I am able to see:The x-drive would be fine for IR diodes. Just use one battery, instead of two. This is because the vf for IR diodes is so low.
If you don't want to have to worry about setting the driver yourself with a testload, consider a AMC7135 based-driver. It can be configured to 1050ma or 1400ma (each chip puts out 350ma)