I bought a flightsuit
on-line and modified it. So, if you're handy with a sewing machine, it shouldn't be too bad. My sewing modifications for the flightsuit:
1. Removed the sleeves and collar.
2. Restitched the shoulder seams. You can make the entire suit a few inches shorter, just by altering the shoulder seams. I was able to bring the waist up almost to my waist and make the crotch the right height.
3. Open the seams of the sleeves, starting at the shoulder, at least part-way.
4. Reattach the sleeves. Because you've changed the shoulder seams, you've made the arm openings smaller -- if they are too small, you'll need to open the seams below them, the sides of the suit, if you can still get your arms through, realize that the edges of the former seams at the upper part of the sleeves will overlap. You can also easily shorten the sleeves when you reattach them. Reseam the sleeves.
5. Reattach the collar. Pin the front edges of the collar in place, then pin the middle of the back. Work out from the middle to get it even, realizing that you'll need to bring it out onto the shoulders a bit. Because you changed the shoulder seams, you made the neck opening smaller. But you probably don't WANT the neck opening smaller, so you'll reopen the shoulder seams, starting from the neck opening, until you've widened the opening enough for the collar to fit into it again.
6. You can also shorten the hems on sleeves and legs, as needed.
7. If you're very thin, you'll probably also need to take the suit in, at least a little, in circumference. Just remember, these things are not meant to be worn tight. I didn't take in any of the girth.
8. There comes a point where you're better off getting a pattern and some fabric. I hate installing zippers with the fiery passion of a thousand suns, so I went the modification route.
I realize, looking at my description, that it sounds a bit complicated. It's really not, I'm just bad at explaining things. If anyone wants to try this method, I can try whipping up a couple simple diagrams that clarify what seams I'm talking about.