Hi guys,
I am planning my first pairings and want your input on conformation. Although I am working with petstore stock for now, I'd like to work towards good conformation in my rats, but I don't have any rat breeding experience, so I'd like your input... I have tried to read the standards and look at the illustrations on different rat clubs, but am not sure which qualities should be of most importance (size, body condition, head conformation, or eye size).

My current group is 3 female blue dumbos (all sisters), one male blue dumbo (their brother), and two unrelated males, a black hooded and an agouti. I tried to get pics of them, but the girls did not want to cooperate and all I got of the boys were their heads. I will list the positives or negatives that I know about each and welcome your feedback on which doe / buck would be the best pairing.The girls are now about 11 months old, and the 2 unrelated boys are about 13 months. So far, none have shown any health issues (except some sneezing from the agouti whom I am not planning on breeding) and there are no signs of tumors, etc. at this point.

Blossom

She probably has the best body condition of the three girls. Not tiny, but not overweight
Bubbles

The chunkiest of the girls, but not what I'd call obese
Buttercup

The best temperament of the females, outgoing and social. VERY active, and also much smaller than the other two girls. I would call her "dainty". Sorry for the blurry pic. She would not hold still.
Howard (black hooded) and Leonard (agouti)

Although it is hard to tell in the pic, Howard has much better ears / eyes than Leonard. Leonard is much larger (close to 1/3 again as big) as the other two males. Howard is smaller for a male but I think he has the best muscle tone. Leonard seems to have a "pointy" nose and does not have the best temperament.
Mojo

Best personality of the boys, very laid back and friendly. Is quite overweight and his eye placement seems odd to me.

What I am thinking:
Breed 2 litters using 2 of the 3 females. If it is unsafe to breed a smaller female, then I will not use buttercup. All 3 seem to have ear and head issues and none of them has especially good eye size (that I can tell).
Use either Howard for both litters or Howard for one and Mojo for the other (if him being overweight is not an issue). Howard has better eyes than any of the dumbos (and head structure I think) so I think he would improve those traits in the females.
Reserve back the best looking babies conformation wise and breed them to *hopefully* end up with better eye size and head conformation in the second generation. I'm assuming that I would probably end up with black standard eared babies in the first generation (if howard is used), then when crossed back, I may get blue dumbos along with black dumbos / standards in the second generation.

Feel free to give me any input you have and thank you for your time / help!