Which progressive scan player for Sanyo Z1?

First of all, please excuse me for writing in English. My German is not that good, but if you reply in German, that is fine with me, but please limit the typical german expressions....

Currently I have a Sanyo Z1 projector hooked up to a JVC NS33 dvd player using a 15m S-video cable

I am looking to upgrade my dvd player to a progressice scan player, as I heard it would improve the image form my Z1 very much.

As the price for the Sony ns730 seems very low (good for a Dutchman), I am looking at this model.

Now I have heard of people that had problems with the combination Sony NS730 and Sanyo Z1. (unsharp image)
I am not the one to play around myself too much with all kinds of settings, but I am able to follow instructions.

So, I have a couple of questions:
1) Is indeed a progressive scan player worthwhile?
2) What progressive scan player can you recommend (is the ns730as good a deal as it seems)?
3) If you recommend / agree with the NS730, how can I prevent r solve the possible complications (unsharp image)
4) What kind of connection should I make between a progressive scan player (I heard you need YUV)
5) what kind (brand?) of cable works well as a connection between the Z1 and the progressive scna player eg. the ns730

Thank you very much for your help, and once again sorry for the English.