Hello Marco,
Yes definitely there are many ways you can implement it and I am pretty sure others will point you to more cool ideas...
Assuming I understand your requirement correctly, personally I would try something like below,
1) I would basically avoid applets on html and instead make use of AJAX calls.
2) Instead of Input Box to enter Plant (werks) I would build a plain HTML Plant List box which is populated with list of available plants by making an AJAX call to Query Template which returns me Plant List.
3) I will place a Grid to display Selected Plant related details, now choosing the Grid you have many choices for instance, you can use an applet grid, or a 3rd party jQuery Grid plugin, i5Grid (if you are on MII 14 or higher) or a SAPUI5 grid.
My personal choice would be anything except an applet grid.
4) So upon selecting the Plant from List box I will make another AJAX call to Query template which gives me required Grid data and then I would populate Grid with data.
As I mentioned above, this one such sample idea there could be many different cool ideas.
Hope this helps!
Regards,
Adarsh