deductions on salary increase

My company would like to offer me an increase. I have the choice of a straight bump-up or I can choose if there are specific benefits I would like that will have a benefit for me (additional money in pocket) and that will be beneficial for them (perhaps less tax they need to pay). I earn a straight salary without any travel allowance or any other benefits that is deducted. Please advise on what would be the best for me and for them?

Do you travel for work?

Not much. Not every month. But when I do its also small distances. 100-300km per month at most.

You could consider a retirement benefit plan (i.e. pension or provident) which would be a way of saving for the future and it would also result in a tax saving as you could deduct the monthly contributions from your income.
Do you have medical aid?