I have a Raven Concealment Phantom holster for my Walther PPS, and I couldn't be happier. It simply doesn't print unless you're trying to touch your toes, but it is a tad uncomfortable in the car. I took my gun to their booth at the 1500 earlier this summer and had one made there in about an hour (otherwise it's a ridiculous wait). It's very customizable, and it is actually an OWB holster in its basic form. I ordered some offset wings and tuckable C clips and made it into an IWB holster.
The cheapest option IMO is a belly band type holster. You can wear it in a traditional 3:00-6:00 IWB position if you want, but you can also move it to under the arm, on your chest, etc. very easily. The only problem is that they tend to shift, especially if you have it around your chest. Also, I would never carry condition 1 because the "holster" part is usually very soft and doesn't protect the trigger enough for me (I only have a trigger safety).
One big plus for the belly band is that your pants don't fall down when you loosen your belt to use a public urinal.
I like the AKJ Concealco I have, others IWB holsters just didnt work for me. Doesn't allow for tucking a shirt but I think it could be made to do that with tuckable clips from Milt Sparks. I havent tried that yet though.