There are some subtleties to paper developers with the various papers, so the choice very much depends on what you want and what you have learned to use. If you are in the darkroom every day, you will use up developer fast enough so that shelf life is not a factor. (I've found that you can not rely on developer that has been in the tray for more than a day.) LPD and the Ilford liquid developers are easy to use and work well this way. If you can use large quantities, the Kodak liquid developers are also a possibility. Or you can mix up a powder formula - more choice but more trouble, too. If you need longer shelf life, formulas with two stock solutions that separate the developing agent from the alkalai, like Formulary BW65, keep for up to a year. (If you compound your own developers, you can mix two stock solutions, one with the alkalai and one with everything else, to get somewhat extended shelf life.) Agfa 130 and similar glycin based formulas, while not that long lived, also seem to last a bit longer than conventional formulas.
Gadget Gainer: have you looked into paper developers at all in your investigations on long shelf life formulas?