I'm assuming that by body lift kit, you mean lifting the body up from the chassis, and suspension lift you mean lifting the chassis up from the axles. I would go for the latter, as lifting just the body doesn't achieve much for a lot of work.
As I said in another post,(somewhere), I changed the suspension of my last two RRC's by fitting +2" Procomps all round and fitting Red/White stripe springs to the rear and Green stripe springs to the front. This achieves a lift of about 1.5", but with much more sturdy suspension, ie it doesn't wallow about like RRC's tend to.
I got all the bits from DLS. (not the sofa firm
)
By the way, both were RRC 3.5 V8's. We did try red/white stripe springs all round, but it lifted the front too much and gave it the look of a speedboat!!
Geoff