I could be totally wrong about this, but it just occurred to me that perhaps a t-strap with a lower vamp might be more leg-lengthening than a Mary-Jane style. I'd be interested to hear what Angie has to say on the topic.
I don't really have any Mary-Jane styles right now, but have had some shoes that have a strap at or near the ankle, and have noticed that a t-strap shoe is a bit less-likely to chop off the ankle/leg at a weird spot. There's still a strap to help keep the shoe on, but it's not placed right at the ankle, or at the high point of the arch of one's foot.
That said - I think a Mary Jane style will definitely work, but am wondering if maybe a thinner strap or a strap with a pretty embellishment on it might be better overall for a party shoe.
Meanwhile, I can relate to wanting some sort of strap there to keep the shoes on. I have a narrow foot with a really high arch, and most shoes just flip-flop all over the place on me.
Here's another one that might work - though, once again - not red patent (the black patent looks dressiest to me):
http://www.zappos.com/sofft-corine-red-hot-red