May I ask why you need to use a urinal? There are plenty of dudes who stand to pee in stalls. Also - why would it need to be realistic for a urinal? Looking at other people's equipment (or just at them in general) in the men's room is highly frowned upon in most places.
For the EZP, 3 things I always see mentioned are slowing down your flow/stopping and starting to prevent filling the cup completely, angling it downward, and making sure it's seated far enough back. I'd play around with it a little more and try those things.
I've used the Number One almost exclusively. It is the only STP that ever worked for me 100% of the time without modification. I've also made my own using small packers with a medicine spoon and some tubing. The medicine spoon stopped working for me after about a month on T because of how much downstairs growth I had. Made it impossible to get a good seal. So that could also be a problem you're encountering.
I can't personally recommend any other STPs, as I haven't used many. I don't recommend PeeCock at all from personal experience. The EZP is what I see recommended most often and what seems to work for people who have had issues with other products.