Ninja: the size is fine but please host the images with www.tinyurl.com and only one pic per post if you are gonna use it in every post. Pixel limit is 400x400 so you can make a pic with both of them in it and then host it with tinyurl.
If you want to use them save them to your comp and put edit them so they are both in the same pic. Then upload it to your photo bucket then go to tinyurl and put in the url. If you dont wanna do that pick one of the two and put the url into tinyurl and it will give you a shorter url. Mkay?