I just recieved my Colt Sporter 9mm yesterday. I have a couple of questions.

I replaced the fixed stock with a bushmaster 6 position tele stock I had on my .223 Bushy. Will the short buffer and spring that came with this stock work with the 9mm. Is there separate 9mm and .223 buffers/springs?

I dont care for the looks of this stock. I prefer the older style tele stocks. Can I use an older style stock on this 6 position buffer tube.

The buffer springs depend on the buffer tube, not the caliber being shot. 9mm/223 use the same spring. You may want to use a heavier buffer to decrease felt recoil and lower some parts wear.

I do not think the older style Colt 4 position stock will work on the newer style 6 position buffer tubes. I may be wrong as I have never tried it.

Where do you get a heavier buffer? How do you tell its Hevier/Lighter? Are they marked?

Did you mean heavier buffer spring?

I have a Colt 9mm upper and I have been using it with my 5.56/223 RRA 6-position stock with the RRA buffer and spring and it has been working fine...  I have also used this upper with a normal A2 stock assembly and it hasn't had a problem...

If I were you, I would just try it and see if it works.  If you have problems, then you can evaluate your options.