MH Conversion Bulbs, Digital Ballasts

Hi everyone,
So I'm trying to decide on a ballast, but I'm confused about MH conversion bulbs. Looking at an htg kit with a digital ballast, but it comes with a MH conversion bulb. I thought one of the main advantages of a digital ballast was that it could run an HPS or MH bulb, but everything seems to be saying I would need a MH conversion bulb which i've heard arent as good and expensive to replace? Does a quality digital ballast like a lumatek enable you to use regualar MH bulbs? If not, I feel like the lumatek might not be worth the extra money other than possibly being more efficient.

I want a 600W setup with an air-cooled reflector, and I'd like to get a ballast that can use traditional MH and HPS bulbs if thats possible so I can have more selection and pick a good quality bulb.

Any help or suggestions with digital ballasts running both HPS and MH much appreciated!

Looks like it's just a standard screen to get more sales that isn't really specific to each item. Since it's in HPS section it asks if you want to add a conversion bulb to halide is all. The one I clicked on clearly states it works with both lamps so as long as it says that your cool.