ST 4 and Touchscreen

[Ullomat]

Hi,

while waiting for ST 4 visual, I am looking for a touch device to use it with ST 4 at the scope. I think it will be a Microsoft Surface. 
I did not use ST 3 with a touch device so far. 
Does anybody use ST 4 (Imaging) with a touch device? Do I need a pen or is it usable with normal "touching"?
I already have a red thin film which does not affect the touch functionality. 

Thanks for any info and always cs,
Uli