oscommerce expert needed for several small fixes or updates

We need a skilled oscommece developer for helping me with several small tasks . Budget is 80 for this and the project is helping me with some small things like: pdf invoice show not correct, the shippingcost show with 4 decimals. help with optimise Google sitemap with seo links optimize oscommerce against malware and few more things I am realistic buyer, and pay realistic too. So if 80 is exceeded i pay extra of course.