For your line, I'd actually recommend home machines.
Industrial machines are great and I use them myself. However, home machines offer more stitch options (home machines have different settings for different stitches, such as straight stitch, zigzag, buttonhole stitch, triple-stretch stitch (for spandex), blindstitch). When you buy an industrial machine, it's purpose is to last an extremely long time and be in constant use at high speeds, but they're usually limited to one stitch (i.e. a straight stitch industrial can't do buttonhole stitches, they have a separate buttonhole stitch machine that you'd have to buy). Industrials are great for mass production and tailoring rooms (I used to do alterations and tailoring), but aren't good for a start-up business where you're dealing with one-off styles. Plus, the high speeds make you prone to accidents (I've been sewing on home machines and industrials and I've never had an accident with a home machine and have had accidents with industrials--got my fingers trapped between the belt and the wheel which hurts incredibly).
Also, home machines are sold with a lot of different feet (as opposed to an industrial machine where you have to order the different feet separately in many cases). Plus, more people know about home machines, so if you have a question, it's easier to find a quick answer. And, most sewing books are written for home machines. Moreover, you can find replacement parts for home machines at your local fabric store, they generally don't carry replacement parts for industrial machines. Furthermore, it's easy to pick up and move a home machine, industrial machines come mounted to a table, with a separate motor, so they're hard to move around (so you'll need the repair shop to come to you, rather than you toting your machine to them, thus more expense).
I'd say once you're experienced on a home machine, then you should consider an industrial.
Here are my recommendations: Home-Kenmore (Bernina is also good), Industrial-Juki.
A Serger is a machine that finishes off the raw edges. A home machine has stitches to finish off the edges, but they look very sloppy, so I do recommend going ahead and purchasing a serger (sometimes called overlock machine). I would not sew the clothes with a serger, as those stitches aren't really designed for seam stability, plus the seam allowance would be way too small (you need a decent seam allowance in order for the clothes to be altered, because more people than you think get alterations done to their clothes, especially high end clothes). You'll need to remember, you use a lot of thread in a serger, so make sure to budget thread money for this machine (look for sales on serger thread)
A serger and a home machine would easily work within your budget.
