man, i ran pro for a month or 2, then i got sportlines..a month later, they SUCK.
Look even if they don't blow, your ride will be totall butt. the stock shocks and struts aren't made for this, i have a feeling they are not designed to be lowered any more than maybe .5 inches and thats stretching it.
Pro springs still give you a high looking ride on a 99-04, you can probably get away with out using high performance struts and shocks, but getting some fox body ones. they are cheap and if they blow, then you can get the high performance ones. stock Fox struts are cheap from the parts store anyway