The issue about rings is "how high". I like a low scope but I think you have to be high enough to clear the magazine on a Notos. If you have "free" rings that came with other guns or scopes I would try them to at least get a better idea what height you need. If you do not have any, you might want to order rings in several heights from Amazon and return the ones that do not work. I do not buy expensive rings, the "cheap" ones work fine for me. They are lined with a plastic tape so the minor lack of alignment that is typical for inexpensive rings does not damage the scope because the plastic tape gives.
For a scope the least expensive I have good luck with is a Hawke Vantage. Mine is a 2-7 but for target work I would get at least the 3x9. Hawke is one of a few manufacturers known for good warranty performance if you happen to get a "bad one". Athlon is another as is Arken. I had a Bug Buster and when it broke UTG ran away and hid. They gave me a return number and then totally would not communicate. So no more UTGs for me. Athlon was totally responsive on one of their scope immediately sending me a new one. No questions asked.
The issue you may have with less expensive tanks from Amazon or similar sources is getting somebody to fill them. They are rated to European standards but not typically to DOE standards. I think the DOE standards are stupid but people who could fill your tank will be violating US law if they do. They are fine if you have your own compressor but a tank plus compressor to fill it is probably more than you want to spend. A DOE certified tank will be more than a compresssor.
If you do not want to hand pump (and for a Notos a hand pump seems like a totally doable option, even if you later get a compressor the hand pump is a usefull backup) I would get a GX CS2. If you order it from GX with their discount coupon it will be about $250 delivered. Amazon is more but they offer an extended warranty and should be trouble free relative to tarriffs. I have not heard of issues with GX but it seems more possible. The GX3 is not a lot more if you like it's features better. These little compressors really use 12V power but come with a 120 to 12 volt transformer. And you can power them from your vehicle.
nwtacticalgear.com 