The sway bar is spring after all and has to be factored into the equation. That'll take car of the static calculation for it. But it's dynamics are harder to quantify since it's attached to the other side... which is moving constantly.
Note: A 1" bar (~25.4mm) with a 5 1/2" lever arm would likely be in that >1000lb range. Out at the wheel (longer lever arm) it'll be a lower number.
Depending on the weight of your car and where you've put things like fuel cells, batteries, and other heavy stuff (like which motor you have) there are lots of empirical threads on this board about how our cars are set up.
I like mine to handle like a cart. It's a 993 motor and heavier than some other engines. So so I put as many things in the front trunk as possible. Briefly...
Front:
23mm torsions
22mm anti-sway bar
Bilstein sport inserts
Fuel cell, battery, BIG oil cooler, fire system in the front trunk
Rear:
200 # adjustable height coil springs
Koni gas-adjustable shocks
no anti-sway bar
I dial in handling with a combination of tire pressures, rear shock settings and sway bar adjustments, in that order.
All of that said, good bushings and solid attachment points for the suspension will transform the car. I use Elephant polybronze bushings with great results.
You didn't say what you want to do with the car but 410# for your rears sounds a bit high. It depends on the rest of your car. On the street that will make you skip over the top of bumps rather than keep your tires planted. That's not really good on high speed turns.
Good Luck