I am no expert but I had a regular slide in range of the GE line of nice, but builders grade (not pro-style) range in NG. I bought a similar, but not as nice model, for a cabin that had to be converted to LP b/c there is no NG. The conversion kit and instructions came with the unit and I did it myself but had my then neighbor who was a HVAC guy inspect it. His comment "As long as you remove the jet insert with the big hole (about 3/16 inch) and put in the jet insert with the small hole (about 1/16 inch), you are fine. However, to make a mistake is really bad." When you compare the jet orifices, it really is not hard to tell which is right at all. Anyway, he passed my conversion as fine. Installed, I could not tell the difference b/t the LP and NG as far as performance, but, again, that was not a pro-style unit. With my Wolf and now Bluestar, they were/are NG so I cannot compare but I do know BS comes configured from the factory. BTW, although it was really very simple, I do not recommend doing the conversion yourself unless you are qualified or have a qualified HVAC/gas tech inspect it (FWIW).

Paso, the internal debate I am having is BlueStar plus single wall oven vs. induction plus double wall oven! My leanings seem to change by the hour. I like that induction will keep my kitchen cooler, and will be safer as my 5 children learn to cook. I also don't want to always have to run the hood to eliminate the CO. And I want ease of cleaning. But.. a range is more romantic, I think my husband would like it better when he occasionally cooks breakfast, and induction may push me to needing another electrical panel in the house, which I think is a $2k expense. I probably need to consult an electrician about installation costs for the two different appliance configurations. Regardless, I'll probably go with my gut, but I want to know what expense I'm in for. Well, at least it's good to know LP will not affect the decision!

Induction is quicker responding than gas, it is simple to cleanup unlike radiant electric which bakes spills on. It doesn't create the waste heat you'll notice in the summer. It heats faster than gas with really good power. If you were a 3 star chef and owner of a best in the world one year restaurant like Heston Blumenthal(Fat Duck) you'd have a 36" Gaggenau cooktop as your home unit. No gas. Search this forum for threads with the many people who once used gas and now enjoy induction. And save yourself big money too.

Looking at the Thermador Planning Guide, there is neither an LP nor a NG conversion kit for any of the Pro Grand ranges. Pro Harmony Dual Fuel have an LP conversion kit, but the all-gas ones do not (nor is there a natural gas conversion kit.) You will need to contact Thermador support to find out what nozzles and regulator will be needed. It's more than 6 easily-accessible nozzles, too, because you have to convert the oven burners as well in your all-gas range. Plus the griddle or grill, depending on what that additional location is. Once you start getting into the regulator and manifold on a gas appliance, you would be wise to have a gas-certified technician do the work.