Here's my recommendation:
T1500 starting stacks:
10 x T5
10 x T25
7 x T100
1 x T500
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28 chips = T1500
Use 1xT500 and 1xT1000 for all T1500 re-buys and add-ons. 7 x T100 starting chips is plenty when using a T5-based structure.
The set below covers roughly 127 x T1500 buy-ins (27 starting stacks and 100 x T1500 re-buys/add-ons):
270 x T5
270 x T25
200 x T100 (includes extras for T5 color-up)
140 x T500 (includes extras for T25 color-up and 100x re-buys/add-ons)
100 x T1000 (used for 100x re-buys/add-ons only)
20 x T5000 (used for T100 and T500 color-ups only)
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1000 chips
The actual numbers required are 270/270/203/141/19 = 1003, but given that the 100 re-buys/add-ons is not a concrete number, the slightly rounded numbers above should be just fine.
Dunno what structure is being used, but I do have a T5-based structure with 20-minute blinds that lasts 7+ hours (plus breaks) for 127 x 1500 buy-ins.