different styles between primary and secondary links

sounds a weird request, but it is basically what i need: different styles (and xhtml code!) for primary and secondary links

for primary, i need a "normal" UL formatted text link, so i can charmily use/override/whatever phptemplate_menu_links().

but secondary links bar is totally different: menu items are image-based and made as something like:

">_logo.gif" />

so, as u may see, i need to alter the whole xhtml structure of secondary links menubar, but i can't since overridden phptemplate_menu_links would affect also primary_links menubar!

an alternative would be to put IMG XHTML code directly as menuitem content, but it seems a shame...what would will happen if i switch to another theme?

i think i should put applicative logic directly on my page.tpl.php page, parsing and formatting $secondary_links directly from there without calling t() functions...but sounds a "not perfect" coding standard...so....its only the last solution to me...

any idea? solution?

tnx in advance!

gabrio

PS i cannot put images as css background: i don't know in advance both the name of menuitem and the size of logo images (probably not equals in width each others) so i eventually cannot size the menu-item LI block accordingly...