From what I can tell, that enlarger can take up to 6x6 negatives, so you will be partly there for 6x4.5. As PDH mentioned, you will need a longer lens for the larger negatives. The lens it has may not be the best quality, but it is likely good enough to get you started. High quality lenses are still fairly easy to obtain, though perhaps not cheaply.
The Meochrom head looks to be a color head, which is useful for B&W and color negatives. The yellow and magenta filters of the color head allow you to print on variable contrast B&W papers without any other filters.
But, as stated, you won't be able to print color slides because the materials for that are not available.
The lamp for the enlarger should be available still, but much depends on the specific lamp it uses.
The wooden base of the enlarger is called the "baseboard", on it you need an easel or printing frame to hold your paper.
The additional stuff you would need would be trays of some sort to hold the chemistry, an easel, a longer lens for your 645 negs a safe-light so that you can see, and chemistry.
If you were in the U.S. you could probably do better than that price, but I don't know what the market is like there.
Many small enlargers do not get a lot of use, so they are often in good condition. But it would be good if it has its instruction manual. You would want to make sure it has negative carriers for all the film formats you would use. You would also want to make sure that there is no hardware missing, though basic screws and bolts are generally easy to replace. But any brackets or other bits that are specific to the enlarger could be very difficult to find.
Ilford has some good information available on how to get started with darkroom printing. http://www.ilfordphoto.com/applications/page.asp?n=9