Human Genome Alignment and Variant Calling Benchmarks
NA12878


My recommendation: download raw reads from Illumina BaseSpace and do alignment yourself. Aligning ~40X worth of human reads takes overnight with ~16 CPU cores.
You can acquire Platinum Genome data from ENA. There is a BAM available for download, but that was done by Illumina's own aligner against a wrong reference genome. You'd better do alignment by yourself. Another problem with this dataset is it is too good to be representative. Modern data are worse.
GIAB provides BAMs here:

ftp://ftp-trace.ncbi.nih.gov/giab/ftp/data/NA12878/NIST_NA12878_HG001_HiSeq_300x/


It is not "typical", either.


SGDP


Instructions on downloading SGDP BAMs are available on this page, in particular this Word document. Warning: you need ~30TB disk space for these BAMs. I also heard it is tricky to download data.
There is apparently a mirror from cancer genomics cloud. I don't know how easy it is to access.