I thought their biggest one was rated to 600?

Fuck them anyhow, if you want big power and a centrifugal charger rather than positive displacment, then...
http://www.procharger.com/models.shtml

Or if want a decent Lysholm jobber for instant boost, then Keene Bell ones dont cost much condidering what they are...
http://www.kennebell.net/pricelist/SC-PRICELIST.pdf