I do a two-table 1M event using 2000/4000 opening blinds (250bb) with a T1000-base set:
starting stacks:
10 x T1000
8 x T5000
10 x T25000
7 x T100000
Runs about 6.5 hours with 20-minute levels, or about 5 hours with 15-minute levels (breaks included). Events usually end prior to L20 (500,000/1,000,000)
typical set:
200 x T1000
160 x T5000
200 x T25000
150 x T100000
20 x T250k or 10 x T500k
10 x T100k chips are used to color-up the T1000 and T5000 chips, and either T250k or T500k chips are used to color-up the T25k chips (depending on which chip set I'm using).