An easy way to see if additional seat height would help is to put a folded towel or 2 on top of the seat. I'm waiting on parts for my Rebel 1100, when I'll get a custom seat, but until then I use an AirHawk seat to add an inch or so.
I wouldn't be too concerned about adding an inch or 2 if you're of average height. Me at 5' 11", I'd even go 3" more. Extra padding is always welcome on cruisers that sacrifice comfort for lowest possible height. Most bikes I've owned had seats over 30" high and were roomy.