slip/crinoline and corset help!

I have my first fitting on Sunday and i need to bring my undergarments. I bought my slip yesterday and I was a little concerned about the length - is it supposed to come down to like my ankles? cuz it doesnt, it hits a few inches above my ankles, like by my shins kind of. Is that how its supposed to be?? I'm tall so everything is always wacky lengths on me and i didnt know if thats where it was supposed to hit or if its just cuz i'm a giant.

Also, I really wanted a corset - not a long line bra, like a real corset. What i loved about the tie up maggie dresses i tried on was they gave me such a nice form and really cinched in my waist - has anyone done this? I'm also kind of worried about doing this cuz i almost feel like between that and the slip its just gonna add more bulk. If i dont do that I'm just gonna wear spanx and call it a day.

Any suggestions?