You could simply buy pro system kit - it is kit of springs and shocks however buying springs and shocks separately you have the same outcome in the end
I have the pro system as well - less drop than HR kit but the comfort is much better.
As to the lowering after 2 or 3 weeks it will not happen. Springs settle down in 2, 3 days max and car will not get lower.
There is possibility of replacing pro kit springs with sport springs.
I have compared part numbers of shocks in pro system and sport system and it seems the shocks are the same. There is only difference in springs...