found a truck

hey guys - i am new to trucks - and finally found one i like after months of shopping - problem is that it needs a couple things - how easy are these to fix - how much does it cost?

- O2 senser
- radiater hose connect/seal - the guy wasn't sure...
- shift control module
he said the module acts up sometimes, and when it does you disconnect the battery or soemthing, then it goes off and is fine

any help asap would be great - thanks

anyone?