Re: Just installed SSL6 in bridge...noise issues!
Do you mean a STK-S6?
If that's the case, the RW middle pickup won't make a difference. The STK-S6 cancels hum on its own and the APS-1 doesn't, so you'll be adding the APS's hum to the STK-S6 whenever you combine the two. If your bridge pickup is a SSL-6 OTOH, it should be very quiet when combined with the APS-1RW, but both pickups will hum on their own.
The only way to have a completely noiseless Strat is to use noiseless pickups in all three positions. SD doesn't make a Strat stack with A2 poles, so your only options would be SKT-S4s (pretty sure they're A5) or going through the Custom Shop for A2 stacks.