Congrats on the new bike. I get my 15 white LT tomorrow, in transit as we speak. At 5'8" I heard where you are coming from being slightly vertically challenged. I would recommend doing the Speedy lowering kit first before getting the Sargent low seat. You already said the stock seat worked fine. I would rather lower the suspension first and have a more cushy seat. Those that have the Sargent seat may say different.