First, there is no such product as magix photoshop! Photoshop is an Adobe product.
You've posted to the Movie Studio area of the forum but I wonder whether you are actually asking about Magix Photostory, since you want to combine pictures and videos into one slide show?
The answer to your question is that either Movie Studio or Photostory will allow you to do exactly what you are asking about. Photostory is very much a cut-down version of Movie Studio (formerly known as Movie Edit Pro) but unless you need its quite sophisticated editing and exporting features, and if your intended output is to a slideshow, PS is more than capable for you.
In addition to @emmrecs comment, it would also help us to advise you more fully if we have more information:
Computer specification, see this topic for what is required and please quote processor and graphics card make/model in full, and also what monitor/screen resolution(s) your are working with.
I would suggest you put this information in your profile signature so we do not have to keep asking for it.
Are the graphics card drivers up to date?
The resolution and format of video files you are wanting to use - a MediaInfo analysis of one of these would help - download and install MediaInfo and analyse one of the clips and post the results, see this tutorial on how to setup MediaInfo and analyse a video clip for all the data required.
Joe, I don't have any experience with Photostory, but Magix Movie Studio is a very capable slideshow creator and you can indeed combine pictures and videos easily. I use it a lot for this. However, there is a major bug in the primary cropping feature (the "Section" effect); it is basically dysfunctional. At this point in time I would advise against Magix Movie Studio for this purpose.