Hi adann and welcome to BFi
Getting the car remapped by a reputable remapper will certainly transform the cars performance as you should see output increases of circa 40bhp and 70Nm
As I'm sure you're aware the N47 engine has had documented timing chain failures, assuming your vehicle hasn't already had the timing chain & its guide replaced ,
you might consider chasing up the info supplied in scottelzo's thread about BMW N47 Timing Chain 'Recall' For Enhancement. that way you'll have piece of mind before you consider a remap?
Have to say the 1 series is fast becoming a firm favourite upgrade for older 3 series owners
Driveway needs sealing, LMK and I'll put you onto me mate Tony.