which would be best twin t3 or single t4

i am trying to decide how many turbo's to use. i have this t4 with 1.11 exhaust a/r and intake .58 what kind of performance can this turbo give on a stock lower end (stock forged pistons) 5.0 with nicely ported heads and f cam with 600 cfm carb and torker 2 intake. what kind of spool should i have. the turbo does not have a wastegate. here is my other options. 2, 86 svo t3 turbo's with the ar. 60 and .48 on the same car which has a 5 spd. and 3.73 gears. it also only has a water pump and alternator on the belt and has electric fan. he is not sure if that is the a/r so he is rechecking them. i heard the .60 and .63 is better. this is a street car that may go to track. i want good streetable boost around 8-12 psi and i don't want to run out of steam. would the single turbo i have be best if these other turbo are infact the .60 and .48 ratings. thanks.

that is what i thought on the different types of t3's. the t4 is came from an international box truck with a 466. i got it for my 6.9 diesel but changed my mind. what do you think would happen if i used it.

the turbo i have has no wastegate so shouldn't it be better for higher flow. how can i upgrade the t4 to be best for me. i am working on getting the t3's. i have a nitrous kit, could i use that to spool it up.haha kidding i am trying to sell or trade it for turbo parts. the t4 really isn't that big looking. here are some pics.