What Are Our Chances of Getting Financed for a Used Truck?

My husband wants to get a truck he found. It has 4WD and I think it would be better for him in the winter. It's like $8988 and with his trade in (stupid buy here pay here car) they would put $500 down and pay the other $500 he owes off. My credit score last time I checked was about a 620 on My Fico and his is a bit lower than mine so I am the signer with the credit and him the co-signer with his income. I make about $300-600 a month and he makes about $3200 a month gross. We have 2 credit cards I put on the app. with about perfect payment history. I am really hoping we get this truck for him but scared of how high a credit score and that the banks need. What do you guys think? Do they check his score or just mine since I am the signer? He had a repo. in the past that was paid off and we are getting our credit fixed now but they probably are disputing it now. Also he has the paperwork to say it was paid off as well. Think we have a chance? I am really hoping we get it....we get a lot of snow and this would be better for him for driving to work.