I have a garage alarm, metal post in front of the locked garage door, cctv, my bike has two locks through it and has a gps tracker. Not sure I can do much else!
I might cost you more for the new controller and wiring for the 60v conversion than getting some lithium! Especially if you're not sure about the wiring.
I think the weight of the bike is the main issue, my daughter has a Viking eco stepper and it copes well with the hills in Yorkshire fine. Doesn't fold so stylish but do able, would be better in a bike bag.
Best thing to do is find somewhere that will let you test ride a couple. Where abouts...
Have you got a limiter adjustment lead like this, you can tweak the pot with a screwdriver and test. http://s192.photobucket.com/user/Forsaken84/media/Electric%20Moped%202KW%20Lithium/IMG_3589.jpg.html
Kickstart.com goes to http://toe-rific.com/. mmm.
My cousin owns a business doing the electroluminescent stuff, he's probably not the cheapest (grr damn you china, he says) but good customer service.
http://www.loopylights.com/