i believe the saddle hieght and wieght are the same (if not, they are very close).
at 5'8 you can easily manage a full sized bike, lemme reccomend the XR250 or TTR250 (not to be confused with the awful TTR225).
of course, if you fit an XR250 (which you would) there is literally no reason not to move up to the XR400. 400 might sound big and intimidating, but its not. the main difference between the XR250 and 400 (from a begginers perspective) is the smaller bike is a bit easier to start (in general).
while we're talking about 400s, have you looked at the DRZ400? its about the same size and wieght as an XR400, but has more power (in stock form). however, its power is still very tame and linear and very well suited to begginers. also, you can get the DRZ400 with an electric starter. this is a very nice option, but it is my personal belief that NO ONE ought to have an e-start first bike. kicking a bike over for a couple years will help you develop a true appreciation on the e-start button.
anyway - i'd focus on the XR250/400 or TTR250. they are simple and bullet proof and all three will leave you much more room to improve than an XR200 or CRF230. the 200 and 230 are GREAT learning bikes, but thats about it (unless you see yourself riding at anything other than a very mellow, very casual rate).
hope this helps.
jeremiah