Any old all metal singer will sew an awesome straight stitch, and shouldn't have a problem with most gear making needs. However, only a couple really stand out for zig-zag and advanced stitching.
Namely, the Singer 401A and the Singer 500A. Those were the top of the line for singer during their respective generations, and they are unstoppable. There are earlier models with more power for really heavy duty use (like thick leather), but they're pretty much limited to straight stitch operation. The 400's and 500's are considered to be two of the best quality consumer machine lines ever produced. They're not industrial but extremely heavy duty.
The 403's and 503's are essentially the same without alot of built in decorative stitches.
There are a couple of other related models that have a solid rep also, like the FashionMate, but for how inexpensive you can get one of the others I mentioned, I don't see any reason to skimp. You can find them on ebay shipped for around $150 in great shape.
I specifically use a 500A for all of my day-to-day quilt work, but I've also got a 301A and a 221 featherweight (both straight stitch only). I've sewn thru 12 layers of the Dyneema X Gridstop material that's used in various packs and that thru-hiker sells, with the 500 and the 301 without a hitch.
One tip though, if you get a 401 or 500, make sure you source the extra throat plate that's setup for straight stitch work, it really helps when working with 1.1oz or lighter nylon.