Hi Rosie8,
I have several folders ... two are Bike Fridays (one I bought new and the other was used), also have a 'used' Dahon Jetstream (about 5 yrs. old) which actually now belongs to my daughter. The Dahon is a much quicker, neater fold than the BF, but not a bike I'd ride for more than 10-15 miles and not in very hilly conditions. The Bike Fridays are built for your specs and are very comfortable ... equivalent to riding your road bike. The stock bikes (not custom built) are around $800 but also very nice. Look for a used BF, if possible, and it'd be best if the seller was around your size.
I love the fact you can just easily put the folders in your trunk and go. Good luck finding the right folder.