You can see every pixel whatever monitor you use. Monitors display at 95 to 125 dpi. If you view your details at actual size (100%) you are going to see every pixel no matter what size your file is - you just wont see all the detail all at once - you would need a gigantic monitor for that. For more detail scrutiny or very fine editing you can do your work at 200% or 300%. A monitor that displays 1024x768 displays less than one Meg of pixels at a time, a 1920x1200 still displays only 2.3 Megs of pixels, so even the highest density monitor is going to let you see only a fragment of your file at a time at 100%.

It is more important to get one with really good color fidelity. I have had the same 17 inch monitor for almost 20 years - a Samsung, that still does not have even one dead pixel, and has controls that allow me to calibrate it. I will never give up this machine until it dies - it is as beautiful as the day I bought it.

Only two curtain-climbers? Try it with six!

Seriously, I think you need to balance three criteria: CPU, RAM and storage. The last you can handle with a smaller HDR or SSD and external drives as you can pick them up.

Also, be careful securing your computer. The three year old should be starting to climb higher and higher. In another year or two, he will be stacking stuff and doing balancing acts worthy of a circus performer; and - as if that wasn't bad enough - he will be teaching his younger brother how to do it too. Yes, there will be sprains and maybe an occasional broken limb in the learning. But they have a reason for wanting to get to Mommy's computer; because it is there.

And then you will be faced with the dilemma that faces so many parents. Which do I press first? - the camera button or the 9-1-1 speed dial button?

Father of six; grandfather of 24+; signer of uncountable casts......

Ah! Mother...

You have a house that has been stripped of everything within about 3 feet of the floor, eh? And until your last rug rat gets to about 4, that's the way it stays! Just don't forget to take 50 or 100 pictures of them each and every day. Today is the last time you'll ever see either of them at that age again. And trust me that 50 years later every memory is important.

Whatever, buy the laptop based only on the cpu. You can add external hard disks using USB 3 or SATA. Then buy a half decent monitor. You'll probably want one that is light enough to pick up and move easily for storage every time you use it, so a 19", 20", or maybe even a 21" would be the limit. Another trick that may be possible is to wall mount it. If it's part of the woodwork it might survive? Maybe not. Have a handy shelf that's 5 feet off the ground right next to where you work!

Why are you editing images on a laptop? This is a critical question, and the route to go will very much depend on this "why".

If you need a laptop for purposes other than image editing, and just are not able to come up with two computers, there might be a relatively inexpensive solution that works extremely well. If you will do almost all of your editing at one single location, but an external monitor for that location. A good monitor makes all the difference in the world for image editing, and a laptop with a good monitor is an extremely expensive laptop. A $300 separate monitor will be vastly better than a $5000 laptop monitor.

Actually, buying two or even three external monitors for different places would still be cheaper than a good laptop!

The only time you'd want to even think about actually editing images when using a laptop monitor is if you travel constantly and have to edit while on the move.

You can get a great camera body, used but in good condition, like a D800 for around $1500.

You then would do well to purchase a 24-70 mm F2.8 lens, used, for around $1400.

This is a very flexible setup that covers you for both landscapes and kids. If you need a longer lens, then the 70-200 F2.8 VR II used, for around $1500.

Nikon still makes an 80-200 F2.8 AF-D - which is still a very good lens - no VR, awful tripod collar, but decent lens quality - the best part is you can buy it new for $1100, or get an excellent used copy for $500-$700.

I would avoid, at all costs, the 28-300 F4-5.6. At best it is just ok, with poor performance beyond 150mm. It sounds like a good idea, but compared to the other lenses, there is no contest.

You still have $1000 - $1700 left in your budget. A second body? Another lens?