You're not going to find one with those limitations. The power of the 9mm requires either a lot of slide mass, or a stiff recoil spring which must be changed often. Such is the case with the Rohrbaugh in which you have to replace the recoil spring every few hundred rounds.....oh, and you can't shoot +P ammo out of it either. It will cost you over $1000 for a Rohrbaugh. There's the new Boberg 9mm pistol, but it is still experimental and it also will run over $1000. Basically, in order to engineer such as small 9mm pistol and reliably deal with the recoil forces involved it takes some refined engineering which costs money and it won't be engineering with a lot of longevity.
Reasonably priced pocket pistols with reasonable expectations of durability, reliability, and longevity are limited to the .380acp or smaller. There are of course smaller revolvers or derringers which are much more reliable and durable in the small pistol format.
I generally don't go any smaller than my Sig P232 .380acp. It isn't as compact and light as the Ruger LCP, but it is a heck of a lot more reliable, durable, and accurate than the LCP. Mine has seen about 3000rds of practice ammo, and about 2000rds of full power duty ammo and it is still on it's original recoil spring. It's grip is also long enough to enable a good handhold which also translates into a more reliable auto pistol. If the pistol moves around in the hand too much or isn't very secure like a lot of pocket pistols, the recoil action of the pistol isn't as reliable and malfunctions do occur more easily.
With all the recalls and problems associated with the LCP at this time, I think you would be foolish to buy one.......at least right now.
Not that "unpopular" guns are necessarily bad, but your options for accessories (e.g., holsters) and spare parts are more limited.
