Hoppes #9 is a cleaner. It is not an oil.
I ran tests, once, to see what products prevented rust. A nail cleaned with Hoppes #9 showed rust in one day. Not an oil.
There are many oils available. The main thing is to put a couple of drops in all the right places. I use Break Free (CLP) to lube the internal parts (trigger and hammer) and moly grease on the rails.
Any oil you happen to have in the shop will probably get your pistol working perfectly. I have put a few thousands of rounds through a 92 and it never failed.
When it comes to ammo, guns tend to do better with one brand over another. This is an individual gun preference. My 92 might like the ammo yours does not. Bullet shapes vary and this can decide what ammo feeds best in a particualr gun.
If you happen to find a box of ammo that shoots particularly well (say, very accurately) then you would be wise to buy a lot of the same lot# right away.
I used to work at an ammo company. We would make certian kinds of ammo only once a year, and the more popular types maybe four times a year. each time we did it, the lot# of the powder would be different, for sure. the powder charge would probably be differrent and sometimes the type of power would be different, depending on what was available.
We would look in the bunker, looking for enough powder to load, say, 5 million rounds of 9mm. There might be 5 different powders available for the job, but maybe only one or two in sufficient quantity. So maybe this lot is loaded with 231, whereas the last lot was loaded with a shotgun power.
When you buy your favorite brand of ammo, if it is a different lot number it could be a very different load compared to what youshot before.
Commercial ammo is loaded to a certain velocity spec and in most calibers there are a lot of different powders that will work. Each compnay has a preferred powder for the job, but sometimes uses something else.
Also, the powder is not cannister grade. Even if they always use, say, 231, the powder they receive each time is a different speed, so they have to adjust the powder charge to suit that particular lot of powder.
The "Dot" powders (Red dot, Blue Dot, Green Dot) are numbered for speed, at the commercial level. Red Dot 1 is the fastest. Red Dot 4 is the slowest. If my favorit elaod is red Dot 4 and I don't have enough, I might load Green Dot 1, instead.
Moral of the story - if you find something the gun really likes, buy more of the same lot #.