I wanted to replicate my original signature on thounds of letters that
I send out but without me physically signing each one of them. In
other words I want an Automatic Signature machine whose signature is
as good as original and looks like pen and ink. Searching in Google, I
found only two sponsored links:
http://www.signaturemachine.com
http://www.realsig.com (Damilic Corporation)

I could potentially rent or buy these signature machines, however
caveat is that it requires that the company prepare my signature
template that can then be used in their signature machine.

I am very wary of sending my signature out to these companies that
they can make a replica template. My specific question is there any
other way that would allow me to do the entire process myself without
having another company prepare signature template?

Have a signature stamp made

Corwin
But if I made signature stamp would that resemble my signature that is
pen&ink or would it like a printed signature. Please clarify. Also
another thing is that doesn't signature stamp require me to provide my
signature to some third party to make the stamp?

Considder the following 

Is the letter you are sending out an official document, if not there
is nobody stopping you from making a 'fantasy' signature that holds no
resemblance whatsoever with your real signature

make a signature that resembles your original signature but has one
identifiable difference , this way you can track if somebody used your
signature from the template provided

just as a general remark , nobody really checks signatures anymore as
a joke i signed several checks which i used to transfer money from one
account to another with a multitude of signatures (some resembling
cartoons) and nobody ever paid notice

I guess I could do what you suggest where there is a subtle difference
between my original signature and the signature that I use for the
template. In my previous comment I had one more question that I was
seeking clarification, would the rubber stamp look as authentic as a
hardwritten signature, in other words can we tell one from the other.
If so what is the best way to get automated pen/ink signature. The
reason i need this because the letter that I send out should look very
personal.

Depending on the maker they can look like the signatures were hand made 
see some examples here http://www.rubberstamps.com/sigstam.html

you say the letter has to look personal , however do any of the people
you are sending it too know your name or signature , if not nothing
stops you from making up a signature (legible or not)

A signature machine produces an effect that is largely
indistinguishable from the real thing. Only by looking at several
copies do you notice that they are way more identical than actually
signing by hand. Since the document is actually "signed" the results
are much better than anything that can be achieved with a stamp.

If you think that the letter that you received from your senator or
congressman was really signed by them...think again.

I believe that your concern, though healthy, is misplaced. Clearly
these companies business depends on their providing their services in
a manner that preserves your security. Of course, all of those letters
that you are sending will have samples of your signature that could be
used for a template...correct?

I'm in the direct marketing business and do this kinda thing every
day. We don't use 'signature machines' because they're way too slow!
The operate much like plotters and, as I recall, are able to sign only
a hundred or two-hundred letters per hour. If you have thousands to
do, as we do, this just isn't practical. Now, I'll assume a quality
laser printed signature isn't good enough (likely because you want it
in color). In this case, we print the signature on the letter, using a
traditional offset press, in a blue ink that resembles a pen. A
typical small press that you'd find at your local print shop will
print 5,000 signatures/hour and cost only about $20/1,000 impressions.
Done properly, you can't tell this from an original! Good luck. Jeff.

I work in marketing for signaturemachine.com and I like to respond to
your concerns. Security is a major part of our business.  Our
customers authorize us to create the template that is used to sign a
name.  These samples are kept on file or we return them to the
customer if they request.

Our equipment can sign up to 450 per hour.  The speed depends on the
signature.   Because our equipment replicates the handwritten motion
(not plotter driven) and uses any writing instrument, it provides a
personnel signature, the same as you signing it yourself; more
personnel than a stamp, plotter, laser printer or printing  press.  We
also offer signing services in-house for those who choose not to
purchase a machine or supplement their own signing equipment.

Please contact us, if you have any questions. I can send you signature
samples. We are a family-run business and have been involved in the
signature business our whole lives.

You could purchase a ocr program such as OmniPage Pro use it to scan
your signature and then in Microsoft word or many other programs of
the same you can insert your signature onto the document before
printing.