Like I said above, you need to read 408.14 and 408.15 for your answer. The answer is right there in black and white.
Your vendor might "like" to sell you a 60 space panel, but cannot.
Your single pole breakers alone add up to more than 10% of the total, and therefore, will not comply with the Code if they are in 1 enclosure.
Like Greg said, the '08 NEC will do away with the 42 circuit rule, but until it is adopted in your area, you are out of luck.
( I notice that your reference came from the'02 NEC).
The ONLY way that you will be able to comply will be to mount multiple panels as the Code requires. You can still have your power panel for the larger C/B's, but will need to have additional panels.
Did the architectural firm give you enough room to do so?
