18" wheels

Hey all, new to the boards but been reading for a while now, I have a question. I am looking to do 18's on my 68 barracuda 340. current suspension mods are:
hellwig front and rear swaybars.
QA1 single adjustable shocks all 4 corners.
hotchkis leaf springs. dana 60 rear.
1/2 hanger offset kit
PST 1.03 torsion bars
front and rear disk conversion (was on the vehicle when i purchased it, not sure what ones it is, looks like 11.75" rotors.

currently im looking at these wheels Rambler - U111 - US MAGS
wanting to do an 18x8 front and 18x9.5 rear. Looking for suggestions on this combo, would like to do a 255 or 265 up front and 295 in rear.

car is currently in the air for EFI install (gas tank install today hopefully) once i drop it back down i will take measurements.

was just looking for advice before i get to that point. I see 72bluNblu seems to be a subject matter expert with these things. Hopefully he will chime in with some advice :)

thanks in advance All,

Kris