I don't believe a registered member of a Prop Trading firm that is a broker dealer can buy an IPO on the offering at all. 5130. Restrictions on the Purchase and Sale of Initial Equity Public Offerings http://finra.complinet.com/en/display/display.html?rbid=2403&element_id=4894
A prop can only trade an IPO once shares hit the secondary market. You can always get the primary delivered into your outside retail brokerage account.
Even if you were a "customer" and not a registered person, IPOs can't be leveraged and must be paid in cash. Bad news Bob