For the "next" button, you can change the class ".hikashop_cart_button{}" and change, for example, the margin.
In the php file "checkout / payment", you can place the line:
<span class="hikashop_checkout_payment_name"><?php echo $method->payment_name;?></span></label>
between <td> tags just after the lines:
<td>
<input class="hikashop_checkout_payment_radio" id="radio_<?php echo $method->payment_type.'_'.$method->payment_id;?>" type="radio" name="hikashop_payment" value="<?php echo $method->payment_type.'_'.$method->payment_id;?>" <?php echo $checked; ?> />
</td>
Or just add a margin-left property in the <td> tag to add a space on the left of the payment name.