I wonder if that bank is too small if the games are going to play deep. My 1-2 game occasionally exceeds $10,000, our record is something like $16,000. I appreciate this isn't normal but it does qualify as "deep".
I expect a deep single full table 2-5 game could hit $20,000+ on the right night, the 1-3 game might run through the $12,000 bank. I see that you are preparing for a 6-max game but I think it might be wise to prepare for a full table. (More so if you are buying custom chips - it is ouchy expensive to get these done in multiple runs and it is hard to get a color match between the runs.)
If this isn't a well established game, I would be cautious about buying a high end chip set. A custom set is going to run $1,000+ and take months to design and produce. Maybe you should test with less expensive chips and see if the game warrants the investment?
In short - I'd bulk up the bank, bigger if you are buying custom chips. I would wait on making a big investment in nice chips until you see how the game actually runs.
It isn't like I took my own advice - though my bank never ever comes close to running out of chips. If I had to, I could put $100,000+ in vintage casino chips from a single set on the table.
My motto: More chips the better, especially if they are nice!
DrStrange
PS shameless brag - over 5,000 chips: