As mentioned, you can use all your lenses that you used on your ME Super, on a digital Pentax body.
One thing that wasn't mentioned is that there are two types of Pentax DSLRs:
1. Full Frame: That currently is only the K-1 and the K-1 II. This will give you the same original view as the ME Super used to give you with your lenses.
2. APS-C: That is all other Pentax DSLR bodies since what, 2005 I think. What APS-C means is that the sensor is smaller, so the field of view will be a bit narrower. The "crop factor" of Pentax DSLRs is about 1.5, which means that a 35mm lens, which is a normal/wide angle lens on your ME Super, will give you about the same field of view as a 50mm lens (52.5 in fact is the field of view with the crop factor applied). Your 50mm lenses will give you a 75mm field of view. Note that the lens didn't change, in this example they're still 35mm and 50mm, but the field of view that they give on these cameras is a bit smaller.
Here is a more detailed explanation:
Understanding Crop Factor | B&H Explora
But in short, if you want your lenses to look the same on digital as they do on your ME Super, get a K-1 or K-1 II. If you don't mind the crop factor and want to save some money get APS-C (APS-C cameras are cheaper).