Some Guerlain men's fragrances are available as EdPs. I don't find that they last any longer or project more. The scent just tends to be more complex and "heavier" where the EdTs are lighter and brighter. If they do last a bit longer, it's usually at the cost of sillage.
I find that's true for the women's fragrances as well - Mitsouko EdP is just richer and more complex that the EdT, but doesn't last any longer or project any more.
If you want it to last longer, the only thing I've found that works is spraying on clothes and carrying around a small travel atomizer to top up during the day. I used to feel the same way, but I change my attitude recently. If I really love a fragrance that doesn't last long, it makes a lot more sense to spray some into a small atomizer and reapply mid day than to look around for something else that lasts longer but that you may not like as much.
The other thing I have found that makes a difference is where you spray. If you spray somewhere that you smell too easily - your neck or arms - you get olfactory fatigue more easily and can't detect it anymore. Now I tend to spray lower on my chest and abdomen, under my shirt so that some spray gets on the shirt as well. With some, I will add a spray to the outside of my shirt at stomach level. That way you get whiffs throughout the day. If you want to smell it strongly all day, that's not possible - your nose will fatigue and you won't smell it anymore.