It doesn't matter that you're currently in the design stage and that you're planning to move webhosts later (or start a fresh install). After all, you design your theme with relative links to resources (images), which sould remain the same no matter what webhost you're on.
This being said, you should make sure to design your custom theme portable: this means (in the first place) to give it a unique name (do not edit the classic theme, but create a copy of the classic theme). Here's the instructions for that - copied from the
preliminary documentation for the next coppermine version cpg1.5.x (that applies for your version cpg1.4.x as well):
Creating your custom theme
To create a new theme, the best solution is to use an existing one as its copy template. To do that, make a copy of the folder of the theme you want to use as a basis. Then edit the "template.html" and "theme.php" files and replace all occurences of "themes/old_theme_dir" with "themes/new_theme_dir" in order for the links to point to the correct place.
Avoid using spaces and special chars in your custom theme name - only use alphanumerals and the underscore (_).
In your case, let's name your custom theme "citroen_showroom". I attached this custom theme (based on the modifications that you have already applied minus the advert crap that you or your webhost injects) to this posting; just download and unzip into
http://brehus5.100webspace.net/Coppermine/themes/ (preserving the folder structure within the archive). Note that I put your background image into the images sub-folder of you new custom theme.
There are various options how you can add your image as a background: it is mandatory that you understand how the greyish background color is being determined in the theme that you're using: after all, it's the body background showing through, which is being defined in your stylesheet
body {
font-family : Verdana, Arial, Helvetica, sans-serif;
font-size: 12px;
background : #CCCCCC;
color : Red;
margin: 0px;
}You could either change this by adding the background-image there, or you could use the inline-stylesheet option by changing
<body>in template.html to
<body style="background-image:url(themes/citroen_showroom/images/antik.jpg);background-repeat:repeat;">This is not related to Coppermine specifically, but basic HTML/CSS. If you need to know details, read up some HTML/CSS tutorials or buy a book about this.