You ought to look at a small rotary table designed to mount on its side first as it will provide you with dual function. Lots of them have dividing plate kit available.
Only progress to a dividing head when you are making enough gears to warrant it. Decide if you need one that tilts (semi-universal). Another variable is the taper, which of MT2 or MT3 etc might be more useful to you.
Quite a few smaller ones that don't tilt around including a couple of ME designs (Sparey, George T) for which castings are available. Also possible to DIY based on old headstock, old tailstock, spin indexer etc. So many options the problem is deciding which way to go.
Another variable is the nose thread if it doesn't come with a chuck fitted. The early BS0 from 'chindia' may have copied the original Browne and Sharpe thread but somewhere along the line it occurred to a UK importer to offer a Myford compatible thread for a bit extra. So they could be something different, including 55 or 60 degree thread even if the right tpi,
Before plumeping for a BS0 I suggest making a cardboard mock up to see how it fits, there must be dimensions on the net somwhere.
A fully universal enables you to index primes but nowadays you can just as easily 3d print a custom plate to enable you to do that on a plain head (see Thingiverse for a plate design you can customise)