Changes to a wordpress template

I am going to setup some affiliate sites using wordpress. What I need is a good template that will be used on all of the sites. So far I have settled with a template by northern-web-coders. But there are a few simple changes that I need done to this template.
My test site is airsoft.sh0p.co.uk
You will see that the front page has 2 columns but if you click on helmets there is only one column. I need all pages to be like the front page with 2 columns. I also need and the picture at top centered and homp page button. Please let me know if this is something that you can do and what sort of cost.

Thanks