Here are some choices.

When looking at HPS bulbs there is really not a lot of choice. HPS is HPS, there is essentially no variation in spectrum or light output. You can get bulbs with a little tweak to the spectrum, but if you absolutely have to have that tweak to the spectrum you would do just as well to add in a couple of fluorescent tubes instead of paying a lot of money for a fancy bulb.

Metal halides have a lot more variation, in colour, in spectral width, in light output, and in lifetime performance. To some extent you have to decide whether you care much about the spectrum and colour rendition that is available if you wish to pay for it, but technology like pulse start and digital ballasts are such a great thing that you would be a fool to ignore them.

Bear in mind that fluorescent technology is every bit the equal of metal halide now in terms of light output efficiency. Unless you really need 400W+ of light or an especially compact light source (which isn't always a good thing) then fluorescents would be better than metal halide. HPS will still win over fluorescents when their spectrum is acceptable.

When you say that "fluorescent technology is every bit the equal of metal halide now in terms of light output efficiency," shrubs, what sort of fluorescent technology do you mean? Compact bulbs, T5 (or T8 or T12) tubes, ordinary or specialized horticultural lamps ...?

no matter what you buy get a hortilux bulb.