No, banks ALWAYS come first. DECOM the factories, you don't need to buy infra anytime soon, given that it's the cause of your problem right now. Factories reduce initial cost, not upkeep. The resulting rise in tank upkeep wouldn't be significant enough to keep the factories from coming down.
EDIT: Examining your nation, I've found these problems:
1. You doubled up a resource. Make sure you don't have two trades with the same resources, you have 5 trades but 11 resources. Although it'd be cool, resources don't double up (i.e. if you have two wines, you don't get +8 happiness, only 4).
2. YOU NEED SOME LAND. You have a 1:10 land/infra ratio, which really sucks. Although it's difficult and costs some moolah to keep up, try and get it to 1:2 land/infra. I'm working on that right now, it increases your environment which, in turn, increases your happiness and citizen count.
3. Get into a trade guild. You have three nonessential resources: LEAD, GEMS, AND WINE. Yes, they increase happiness, but you should go for bonus resources that give you more happiness and reduce infra upkeep/price. Go for the construction/beer/fast food set, for an example of the resources needed, check my nation. Given your resources, you could also go for one of the high-end sets, whose bonus resources escape me... lemme see... cars, asphalt, microchips, radiation cleanup, construction, and beer I believe. Very nice set.
The following are speculations, given that I can't confirm them without spying on you.
4. Are your trade partners on black team, or are you mixing color? Try and get all your trades on the same team, that's 5 happiness right there.
5. Is your gov/religion what your people want? Religion should always be adjusted, but tell me what your people prefer on gov. If it's revolutionary, be revolutionary. If it's republic, be republic. There's one other case, but I can't remember it. See if your alliance has a government choice guide.
Other than that, you're good. You have a nice resource drop, so you have possibility for any set. Gold is a needed part of the big set I mentioned, and can be used as a "luxury" resource in any other set.