Help editing a theme

I have set up a site at http://www.bingoformen.com/. As you can see the front page is thrown all out depending on how many words I use in the first paragraph of each post. Is there any way of changing this so each box is a set size or even better changing it so instead of two rows I just have one row with the 6 most recent posts.

This is the the main index code:

<?php
get_header();
?>

<?php $count = 0;?>
		<?php query_posts('showposts=6'); ?>
	<?php if (have_posts()) : ?>

<?php while (have_posts()) : the_post(); ?>

<div class="postindex" id="post-<?php the_ID(); ?>">

<h2><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h2>

<div class="entry">
<?php the_excerpt(__('Readmore �'));?>

</div>
<div class="spacer"></div>
	<ul class="post-data">
	<li class="comments">
<?php comments_popup_link('No Comments &raquo;', '1 Comment &raquo;', '% Comments &raquo;'); ?>
</li>
	<li class="posted">
<?php the_time('F jS, Y') ?> by <?php the_author() ?> <?php edit_post_link('Edit','',''); ?>
</li>

</ul>
</div>

<?php comments_template(); ?>
					<?php
					if($count == 1 ) {
					echo "<div style='clear:both;'></div>";}
					$count = $count+1;
					?>

<?php endwhile; else: ?>
<p><?php _e('Sorry, no posts matched your criteria.'); ?></p>
<?php endif; ?>

<?php posts_nav_link(' — ', __('&laquo; Previous Page'), __('Next Page &raquo;')); ?>

<?php get_footer(); ?>

Any help greatly appreciated thanks.