Vortech is one of the best companies for blowers. I have a Vortech S-trim. 5psi is not a lot of boost. You'll feel the difference but it wont be pushing you into your seat. If your talking about the kit, I think they are advertised as 5-6psi but there's more there.
If your keeping the engine stock, that about the boost you would be getting. Change the TB, MAF, Intake and you'll probably hit 10psi. I would go for the Vortech