Concrete Mold Making & Casting

I'm a custom mold maker. You can contact me at <email>

As for not disturbing the original, it depends on what the sculpture is made of. I can help with that.
Judy

I generally try to create my own molds- there are some really cost effective, easy-to-use products, but you must make sure that you choose your products with care.

If they arrive on time, Townsend Atelier's Knead a Mold and Brush a mold, which work in conjunction with their Swell Shell, are easy to use. Beware, though. Townsend Atelier has great customer service until something goes wrong. Townsed Atelier's customer service folks take your money, make promises, and then you may have to wait months for your product to arrive.

I recommend trying to make your own molds, but stay away from Townsend Atelier.

To answer your question directly I don't know of any company that makes molds specifically for your application. I do know, however, that people have come to me with this exact same problem.
Whenever I make a mold I try to reassure the customer that a successful casting may mean degradation of the original. I've been fortunate to have had great success in not damaging originals.
The secret, as others have mentioned, is to match the molding material to the model material.
I find urethane to be very forgiving, btw.

Tin cured silicone is not affected by sulfur in clay. Any tin cured silicone should work just fine as a mold rubber. If the sculpture is in soft clay it will be damaged by the mold process, however, once you have the mold you can make as many as you want just like the original!

Most of the time the original gets damaged in the mold making process. that is why it is important to use a high quality silicone for the mold so you can make exact duplicates. If it is a clay sculpture it will get damaged .
www.rtvmoldmaking.com

water based clays can also cause problems with inhibition as some rubbers will not cure against wet surfaces; or if they do they may not produce the result you are looking for...

which ever rubber you use, you MUST know about it's compatibility with the model surface or what the model is composed of... otherwise you risk destroying your model and wasting money on mold making material because the whole experience failed.

if it's something you don't want to devote time to, hire an experienced mold maker; here's a list of mold makers for hire:
www.smooth-on.com/p101/Moldmakers-Exchange/pages