[jdiehl]

Just looking at a version 4.2.2 installation which is different, but in this area might be similar. I opened:
skin1/modules/Product_Options/customer_options.tpl

And around line 50 I see:

                {strip}
                  {$o.option_name|escape}
                  {if $v.is_modifier eq 'Y' && $o.price_modifier ne 0}
                    (
                    {if $o.modifier_type ne '%'}
                      {include file="currency.tpl" value=$o.price_modifier display_sign=1 plain_text_message=1}
                    {else}
                      {$o.price_modifier}%
                    {/if}
                    )
                  {/if}
                {/strip}

As you can tell it prints the option name first and then prints the modifier depending on if it's a price or percentage. Just surround that with {* *} to make it a comment, save and test. (don't just deleted it it's handy to be able to put it back.