Hi Pamela,
Find a local shop and find a suit that fits. This especially true if you are not a slam dunk stock size. You may spend a few $$ extra but you'll walk out with what you know fits. Consider your investment in this sport and your trip and write the difference off as cheap insurance.
There's nothing special about that brand. Remember fit,, fit, fit. See if you have a Bare dealer, they have the biggest size selection.
I would do this ASAP since from what you say a custom may be in your future. This is a common solution for many divers for many reasons and the cost in just a bit more thank a good off the rack suit.
I do think ST is one of the online sellers what will send several suits if you want to carry them on your credit card and you keep the best fit. This helps but not every brand will have a cut that fits you so you can still get beat up with shipping charges.
Do not roll the dice.
Pete