Thoughts on ride height???

[FRENCHBLUE72]

Im needing to set-up my watts link but need to figure out my ride height. So guys whats the best way of doing this I am still needing my drop spindles do I need to wait or can I set-it up now? Right now I am running 15 wheels and tires but am gonna step up to 20''s do I need to take that into consideration? Any helpful info or insight would be great..

set-up I have now consists of

front
stock 72 spindles ( soon to be ordering 2 1/2 drop spindles)
strong arms
firestone bags
1 1/2 drop crossmember

rear
2'' blocks
bags are on order but will mount to the trailing arm
flipped center crossmember