For beginners, I highly recommend Chuck Adams' code course.  It has over 20 hours of practice materials and is free from several sites on the Internet.   It is in the form of mp3 files so you can use it on your computer, and s .pdf manual is included.  It is very well done.

I believe you can also obtain it from the FISTS site.

Just search for Chuck Adams, K7QO.

VIZKEY makes left-handed single paddles for electronic keyers. and also manufactures left handed semi-automatic (bug) keys: www.vizkey.com .

VIBROPLEX manufacturers left-handed semi-automatic (bug) keys: www.vibroplex.com   .

Probably BEGALI makes left-handed single paddle keys as well, but I don't know.

It may be that both W5LZ and W0WCA are correct.  I notice that the dot speed can be varied quite a bit simply by adjusting the tension on the Dot Spring (hairpin).  To achieve the slowest dot rate with the weight as far out on the end of the bar as it will go, the Dot Contact screw must be backed out almost to the point where the Dot Contact doesn't make contact with the contact on the Dot Spring when the pendulum is at rest.

Brian, VE2AGO, mentioned this is his QST article, "Semi Automatic Key Adjustment," posted as a .pdf file on the Vibroplex Site:
http://vibroplex.com/original_bug_adjustments.pdf

W0WCA did not mention whether he varied the Dot Spring tension as well as moving the weight when he made his measurements, but W5LZ may be referring to this when he said: "Very roughly, something on the order of 20 - 40 wpm with the standard weight, as already said.  That's a typical range of speeds, the exact range (if there is such a thing) will depend on your adjustment of the bug.  Lots of 'play' in that."

For those who may want heavier weights than those sold by Vibroplex, 2B RADIO PARTS, 2bradioparts.com ,
sells six sizes of aftermarket weights:

1.2, 1.6, 1.8 and 2 oz. standard width weights.

1.7 and 1.9 oz. "wide" weights.

Like most, I learned CW by ear.   However, the cw readers may be a good learning aid.  See the character, hear the character....., see the word, hear the word ......  I imagine most people want to copy by ear, but this may be a way to get there.  If so, it's all good.   

In former times, the decision was simple, train by ear.  There was no other way to do it.  It must have been brutal in the days of straight-key telegraphy.  The punch-tape players made it a little easier, and cassette tapes were still more convenient.  After years away from radio, I'm trying to get back to 30 wpm, and I'm using mp3 files from the ARRL code archives.  Perhaps we are just set in our ways and these cw readers deserve another look.

Regarding my question, here is the reply I received from Vibroplex:

The low end range of the bug with the stock large weight is approx 20 WPM.  The bug was built as a high-speed device and it's stock range is approx 20-40 WPM overall with the large weight.
 
You can add more weight to slow it down some - we sell a device though specifically for that purpose called the Vari-Speed.  Take the weight off, put the Vari-Speed on, then attach the stock weight to the Vari-Speed - low end 13 WPM or so.

Possibly the winning bidder wasn't around in 1960 to buy one for $5.50.  In
1960 my Grandmother used to give me a silver dollar when I cut and raked her lawn, and
I would immediately go and blow the whole sum on toy trucks.  She told me
that I should be saving those for the next Great Depression.  Turns out she was right.

The Vibroplex Original currently ships with the No. 401 (one ounce) weight.  Does anyone know
the approximate speed ranges of the key with, respectively,

The No. 401 (large) weight?

The No. 402 (4/5 ounce - medium) weight?

The No. 403 (2/5 ounce - small) weight?

FB!

In a month you will be dashing them off like a champ!

I'm late to this discussion, but as a fellow left-hander I encourage you to stick with a right-handed bug.  If you have a version with a knob/paddle assembly, you might reverse it for the ergonomic benefit.

Vibroplex, Vizkey and Begali will all be happy to build a left handed bug for you, but you are likely never to see another one.  If you see a classic bug come up at auction you will be out of luck.  If you want to operate a bug at a Field Day station you will likely be out of luck, unless you bring your own.  IMO, that's too limiting.

Some things that are right-hand oriented are a serious pain for left handed people to use, but moving a lever back and fourth is no big deal.  So what if you are doing it 'backwards'?  Using a bug key is a much less useful skill if you can't sit down and use most of the equipment you are likely to find.

Here is KR1ST's web page relating to his apartment magnetic loop antenna.  He adds capacitance by using lengths of coax that he can patch in as needed:

http://www.kr1st.com/magloop.htm

If you can get any kind of signal out at all, my suggestion also would be to try a small, tuned vertical loop.   They are easy to build.  Here are two websites that provide all the information you will need:

http://www.qsl.net/pa3hbb/magloop2.htm

http://www.aa5tb.com/loop.html