Well here is your real issue, 18" rims. I have 275/60 on 15's and they're better than street tires but nothing special. I'd run a MT on that rim size and hope they don't spin at 50mph.
Years ago, in a Road and Track interview, the host proclaimed, "Horse power is good! More horse power is better! But, too much horse power is simply sensational!"
Any questions?
I'd start getting the current power you to have to hook, if that means MT Street Drags or ditching that rim size than so be it. From there it's all about E.T., you can say I dyno 400Hp 500Tq but if the car only turns a 12.2 than it's irrelevant since guys on stock turbo's are doing that with much less power.
Hooking first, power second.