buy the bike that you feel comfortable on in the riding position, that's how you'll spend most of your time on the bike and then get it lowered.
I bought a new shock for my bike, but you can lower a bike in many different ways and different costs.
The other thing to make a note of is the handling, ignore being told it will change the handling of the bike.
Yes it might do, but if you get it lowered by some one who know what they are doing they'll do it properly AND if you buy the bike and get it lowered with out riding it too much beforehand then YOU won't notice any difference in the handling.
I bought my bike and had the shock put on quickly and my bike is brilliant, I love it, I'm flat footed (that was a very big deal for me) and I never think twice about riding it, my previous bike I'd use any excuse not to ride it!
pm me if you have any questions.
