Yes, it is preferred to get a dedicated monoblock for sub... the MRP-F240 might not have enough juice to drive the type E sub cleanly at large volumes, if you are not careful, it may lead to premature death of the sub (running square wave, from an over-driven amp, into any speakers is always a no no).
Here's my sub setup, still on my other car that is...
Amp: Alpine MRP-M350 (200W RMS 4ohm, 350W RMS 2ohm)
Sub: Infinity Kappa Perfect 10.1D, dual coils wired in parallel for 2ohm, 350W recommended input power, 1400W burst.
Sub case: 0.6cu.ft. sealed
Both the above were bought in the US of A, amp was US$150, sub US$120. Sub case and installation done here locally, RM350.
LCP