Is a wire transfer the only way? I'm not near my normal bank who requires you to be in person to wire money so I'd prefer another option if it exists
The only answer is to simply use ofx.com (or a competitor such as transferwise.com)
Sending a "wire" is laughable in the US. Don't even bother.
(Don't even mention that the exchange rate you'll get is crap.)
It's a nuisance to set up an account at ofx or the others, but once it is in place, everything is dead easy, one click.
Source, we do this dozens of times a month. (And fwiw I owned various money-transfer related companies, though mainly drunk at the time. But still.)
Definitely not the only way.
Most banks will write you an international bank draft (like a cashier check but in in any currency), payable to anybody. They might mail it direct to the company, or mail it to you so you can mail it to them. This is usually the cheapest way to send large amounts.
If it's a large company they may have a US branch or a US dollar bank account, and thus take a check in US$.
If your invoice is less than $10,000 you can use an International Money Order.