LTR is the best visa available if you qualify for it. Its cheaper than the other options long-term and offers much better benefits, including tax free status on foreign income.
most agents are no longer offering bank account services unless you also purchase a non-immigrant visa service from them as a total package. I don't know if any agents that still offer assistance opening bank accounts for people on tourist visas.
Originally the banks were telling people that they could open accounts if they were married to a Thai or owned property in Thailand, but I've also read reports that banks are saying that's no longer the case and shutting those accounts as well.
You shouldn't have any issues getting a non-O visa both times. That will let you get yourself setup for success on your 2nd entry.
Make sure if you didn't get married in Thailand that you get everything you need to register your marriage in Thailand before you leave. There are things you must get done in your home country before traveling or you won't be able to register the marriage.
First of all, there's no such thing as an exit visa. There's a re-entry permit, which you would need to purchase if you don't want your permission to stay stamp in your passport to become invalid when you leave Thailand.
A re-entry permit does not give you any extra time. When you leave, the date on your permission to stay stamp remains the same, and you would need to be back before it expires in order to apply for an extension.
So if you arrive in February with a 90-day non-O visa, your entry stamp will give you permission to stay until May. If you leave between February and May with a re-entry permit, you would still need to be back by May to apply for your extension or your stamp will expire.
You can either apply for another non-O when you're on your trip, and then wait 45-60 days after arriving again in June to apply for the 1-year extension. Or you can arrive the second time as a tourist using visa exempt, and then apply to convert to non-O visa at your immigration office since you'll already have a funded bank account.