Not familiar with your kit, so the following is general comment only.
Consensus here seems to be that bi-wiring is at best marginal.
Bi-amping is more open to debate, but general view is that it's a good thing, although buying a more capable single amplifier is better (unless you can go active) - it will cost less than the two amps together needed to bi-amp, but more than the second power amp as an upgrade. You pays your money, you takes your choice! You're certainly not going to achieve a £1000 amp sound by spending £400 each on an integrated and a power amp - you don't get nothing for free and there's no magic. What you might get is a very cost effective upgrade if you don't have that £1000 to spend but you do have £400. My opinion.
What you need to bi-amp is a pre-out on your integrated, a gain matched power amplifier, an appropriate interconnect, bi-ampable speakers, and bi-wire speaker cable. Hook the lot up, do not under any circumstances forget to remove the connection between the terminals on your speakers (expensive noises and escaping magic smoke if you don't) and off you go.