I have used an Ibanez Jem 7v (Steve Vai, not Jason Becker) to demonstrate sweep picking. I have set it up with skinny top-heavy bottom Ernie ball strings with the tuning all dropped to D flat. I find that heavy gauge strings and lower tuning leads to a lower fundamental giving more harmonic content. I also find that string bending is easier with less tension. You have to watch out for fret rattle when down tuning which can attenuate the lower harmonic frequencies reducing tonal response. It really can make a difference to your playing (just listen to Zakk Wylde and SRV)

As the Diamarzio Evolutions in the Ibanez are quite high impedance, I try to hit a preamp as soon as possible in the signal chain in order to prevent loading them down. Loading tends to give poor low and upper frequency response leading to a mid range hump (muddy sound) some people try to get around this by using active pickups. I personally prefer using weaker vintage passive pickups which tend to have a lower impedance leading to more tonally satisfying sound, but you do have to make sure they are well insulated because the signal is lower and tend to carry nasty noises with it when gain is applied!