Hello,
Dead time is the time between the off transition of a low side mosfet and the on transition of the high side mosfet, and vice versa. You can have varying Ton and Toff to generate PWM, but the dead time is to make sure that you have break before make behavior in you H bridge.
If you have make before brake, supply current will shoot through both mosfets resulting in high current peaks, heat, EMC problems, device destruction, etc.
I don't know what is in your library, but with controlled voltage sources, switches, limiters, etc, you can easily make your own driver if this circuit is to learn basics of power electroncis. Multipliers, switches, VCVS, etc are not real components, but just mathematical function blocks in spice that enables you to create lot of functions.
It will make your simulation faster and you have full control over everything, without the limitations in opamps. Other thing, to have some control over dV/dt and dI/dt, actual circuits contain gate resistors frequently (to reduce EMC problems).
If you want to simulate something that you may build, try to locate a full or half bridge driver, or high side driver. Maybe you can use the search function in your library.