SYIC is what is now called Techniks. Top quality, equivalent to Kennametal for those types of collets. If you're missing any sizes, let me know as I think I have some of the smaller ones.
I've got a 300S on one of my benches and it's a handy little vise, but definitely on the small side. I've been in so many machining and fabricating shops over the past 10 years I've lost count, and the most common vise you'll find is the 450S...big enough for serious work, but doesn't take up too much bench space, or put the work too high when it's mounted on a normal bench.I bought and repainted a 3" Wilton bullet vise a few years ago and although I love it to bits, I've been keeping my eyes open for a bigger one. Finally managed to get over for a price I could more or less justify. It's a 450S, 4.5" bullet, weighs around 70lb! Needs a little bit of love, v but works very smoothly. I'm not going to paint it, it's going to stay just as it is