Tenson
I have just hunted out the manual for my Hydrovane compressor, it has a 2.2kw motor and knocks out 9.5CFM @ 100 psi so probably 30psi if sucking would increase the capacity(sure someone on here could do the calcs) but i can't see that e-bay pump knocking out 8CFM and don't forget that's free air delivery once you get it loaded that figure will drop. Hope i am wrong as i just had a look on e-bay & it looks like someone has just bought one.Just my thoughts.
regards Mike