[LAU] OT: Portable Keyboard

Hello everyone. I'm posting here more out of desperation- I simply cannot find what I'm looking for anywhere. Basically I'm looking to replace my Evolution MK-461c midi controller with something of a little bit better quality, and something capable of producing it's own sounds (relying on a computer is often quite inconvenient, especially since I haven't yet managed to find/setup good enough quality sounds). The main problem I'm having is finding something portable. My MK is 5 octaves (61 keys), and measures approx 97cm x 23cm x 9cm. The main point is that this thing is a long rectangle. Every single other 5 octave keyboard is getting on for square- with the same length, but having a depth of about 60cm instead of 23cm. What is going on? I know they put the speakers in there, but seriously? That's hardly portable, and I *know* the additional electronics doesn't need to take up that much room. The other serious problem with these is that they aren't even flat squares - that I might be able to deal with, but all the ones I have seen are more like wedge shapes and end up being stupidly high at the back as well (again, well over twice the height of my MK). The other major problem I have is that I need line out rather than just a headphones socket. The main problem with the headphones socket (aside from not really being as good for connecting to a PA system) is that it mutes the speakers, which isn't very helpful since I'm likely to be using PA systems without foldback capability. It seems that I have to go to digital piano before I get line out. Actually, weighted keys would be nice, but again, I have to go to digitial piano to get that, and digital piano's are all 7.5-8 octaves, which doesn't fit in my car. I've considered the possibility of a 6 octave, but I don't think that will fit either. Does such thing as a "portable keyboard" suitable for live performance actually exist? Oh- one other thing- price is a major consideration (I originally bought the MK because it was cheap). I like the sound of Yamahas, and I nearly bought a PSR-E403 off ebay, until I saw a better picture and discovered that it's a stupidly high wedge, and that it has no line out. Please, can anybody help me? Thanks. Simon