If you don't have much to spend (and nowadays, that's most of us!) I'd suggest you go for fewer, but better quality chisels. Chris Schwarz advocates 6 sizes (1/8", 1/4", 3/8", 1/2", 3/4" and 1 1/4") that will do everything a furniture maker needs. If you already have some chisels, you could cut that down to one small, two medium and one large (say 1/8", 3/8", 3/4" and 1 1/4"), which will do almost anything most of us need. If you do find by experience that there's another size you really can't do without, you can always add it later without feeling guilty.
It's human nature to accumulate stuff, and most of us have far more chisels than we really need. The vast majority sit in the rack doing precisely nothing for most of the time. Given my time again, I'd take my own advice above, and have far fewer. Not such a storage problem, you get to know each tool and it's balance much better, and less cost.
As to brand, I agree with most of the comments above. All those named (Ashley Iles, vintage, Narex) are either good or superb. In the end, it's down to personal preference.
