Sunquat is a hybrid between kumquat and Satsuma, and may be a tinier bit hardier than Satsuma.
That may be a good one for your climate.
There's also Arctic Frost Satsuma (a Satsuma x Changsha hybrid), which can be a little hard to find, and if you do find it is likely to be kind of expensive.
Mine unfortunately didn't survive here in zone 8a, but this is in the PNW, it got planted outside too early last year and had trouble adjusting to the temperatures, suffered dieback, wasn't that strong so might not have been able to have the energy to survive the following winter, and was planted in a colder part of the yard that got little sun during the Winter. I suspect it would probably do much better where you are.
My personal opinion, with very limited funds, you're probably out of luck.
No one can easily answer your questions, unless your questions are very specific, and you're willing to accept some vague very simple answers.
Your best bet would be to go back and read some of the old things posted here.