BAM file download for just a few genes

Hi all,

I want to download the BAM file just for few genes and because Don’t need the whole data of patients, I can download it by my interest gene position.
I tried to find my gene position in the UCSC and RefSeq, but they showed me different positions -very small difference- (I set my Reference genome on hg19 in both sites). Now I don’t know which one should I choose for download?

Could I randomly download 200bp upstream and downstream of my gene position?
Does anyone have the same experience?