I have had both a White (very old) and a newer Bernina (1350?). Are you comfortable with adjusting tensions on something like an old Singer or a long arm quilter? If so, you will just need to bite the bullet and learn how to do it. There is definitely a learning curve for a serger - threading, tensions, inside corners, outside corners, curves - that you will need to spend some time with. In the classes I got with my Bernina serger, we tried lots of different types of threads and stitches, retreading and adjusting tensions with each one. I got good at it by the end of the classes. The key to retreading is just to be orderly about it and follow the sequence. BTW, there are some great accessories for most servers. My "elasticactor" foot to apply elastic is tremendous! I do not like auto-tensions. I am picky, and I want to control tension adjustments myself. Threads and fabrics just vary too much. Then again, I have vintage Singers, a multi-needle embroidery machine, and a quilting machine that all have manual tensions so I am very comfortable with adjusting.
I would not not recommend getting a cover stitch machine like I did. I was convinced I would use that capability, and I haven't done a thing with it except in class. It is a pain to convert, and it would have been better to get a separate inexpensive cover stitch machine and the basic 4 thread serger. It would have been cheaper and easier.
I second the the concern about using a serger for quilting, but they are wonderful for clothing construction and home dec.
Pam