My small credit union in the US allows me to send checks from my HSBC account here, in ££'s, and they convert it to $$ for me, for free! All I have to pay for is postage. It does take a week or so for the check to be converted and deposited. I suggest you check with your bank in the US, as I know for me, I wouldn't have even thought of asking (but my mother told me to!)
I ran into problems because I consolidated and the new company didn't accept credit cards, or foreign debit cards...if yours does/will, I would consider just getting a credit card here and paying your loans monthly with that. If you are good at repaying in full every month