Mole',
I think 'Nye Viking' made a "Classic Oval" key at one time that was probably one of the most common of the 'professional' keys. They were all brass (I think) and were made to bolt/screw onto a flat surface, desk, stand, whatever. They also had a 'shorting switch' for land telegraphy use. Nothing special to look at, but about the only way to break one was to beat it with a sledge hammer. The contacts were fairly 'hefty' because of the current/voltages commonly encountered. I learned on one and still have here somewhere. I haven't seen one advertised for sale in quite a few years, but I'd bet they still make them.
To send good Morse code you have to know what good code sounds like, you have to have listened to it for a fairly long time. You have to do that to learn and build speed with code anyway, so it isn't all that big of a deal... sort of. Duplicating that good code can be a real PITA! Basically, it's learning the 'translation' of sound into hand movements, which is just a matter of practice. And until you build up the appropriate muscles, you are going to know what sore feels like. 
Doesn't really matter what kind of key/bug/keyer you want to learn with, they'll all put you through the same 'sore' stages. Of any of the three basic kinds of keys, the straight key requires the most hand/wrist movement so will be the most 'work' intensive to learn with. The semi-auto (bugs) and automatic keyers are easier on the muscles. Learn with which ever you feel like learning on. They all require some 'set-up', the 'bug' more than the rest. Oh, that will be lots of fun all by it's self! It's really not that bad, but it is definitely different.
There are three brands that I like, Bencher, Nye Viking, and Vibroplex. There are a number of other brands, and quite a few of the 'custom' sort of key makers. Find one you like and play with it.
- 'Doc
Oh, forgot. If you want to use a straight key, find yourself a nice -heavy- base to put it on. They will move around if you don't.
