I am new to the site and need suggestions.

My old, basic Kenmore machine quit on me around Halloween, after furiously sewing five complicated costumes last minute for a band to perform in at their annual Halloween Ball and another friend's costume for Voodoo Fest. It was already on it's way out, being that it was about 8 years old and the tension was never quite right, no matter how much adjusting I tried. It decided to quit while I was sewing really slippery, plastic-y liquid silver fabric for another costume.

My friend felt guilty for the Kenmore failure and lent me her Brother CS-6000 to use for clothing alterations, as that is what I do on the side. I was in love with it until I tried to put buttonholes in a thin wale corduroy blazer. It does NOT like corduroy! So - I need a machine that has the same functions, especially the buttonholes, but allows for heavier fabrics. I will be doing alterations mostly on shirts, suits, jackets, and vintage dresses, as well as the occasional costume.

Thank you in advance for any help!