Yes, potato ricer would be an ideal choice for gnocchi making, and if you enjoy them as well as mashed potatoes, potato pancakes and various other recipes that uses pressed/squished potatoes, it would be well worth an investment, as it shouldn't cost that much and it is very handy.
However, without it, you can just use a potato masher and squish them as much as possible, as Haggis said when you precook potatoes leave them whole with skin on, steaming or pressure cooking would be the best way, as you would want as little liquid as possible getting into the potatoes.
Also it is true that the recipe can vary according to the quality of potatoes. It is difficult to get just the right kind of potatoes, I often end up adding much more flour than what the recipe calls for to make the dough solid enough. You have to kinda play by ears, just feel the dough while you are kneading it and while making the "ropes", and if it feels too flimsy and soft, you need to add some more flour until it attains the body that is robust enough. Also when you store them in the fridge, use plenty of flours preferably to coat each morsels to prevent sticking to each other and to absorb any existing excess moisture.
When you cook them, don't put too many in one go, and scoop them up as they rise to the surface.
For sauces, one of my favourites is quattro formaggi, well...to be honest it is one of those things that you are not "allowed" to give a thought about just how much calories you are packing in as you enjoy it, but it is just a brilliant occasional treat, well worth a try. My usual combinations are gorgonzola, taleggio, fontina and edam (or gouda), cut them into small cubes, heat them up in a double boiler, add desired amount of cooking cream and a dash of white pepper and let it cook, stirring frequently, until the sauce become completely smooth. They are just gorgeous, and if you cook some broccolis on the side to enjoy them with this sauce, mmm, mmm, mmm... it will make you totally forget about velveeta!!