Like OleCuss said, for slightly more than $500 the Orion XT8i is available that has sufficient aperture to serve you for a lifetime. Also, don't base your decision upon packaged eyepieces, etc as these are things you can add slowly over time. Consider the telescope and mount as this part is fixed.
The telescopes on your list, while all excellent telescopes, really fall into two categories .... telescopes with stable viewing platforms and telescopes that shake and vibrate.
Two telescopes, the Orion XT6i and Celestron 4SE have very stable viewing platforms that will greatly enhance your viewing pleasure. The other telescopes on your list are nice but not in the same class as these two.
The Orion XT6i has sufficient aperture to show details of deep space objects and serve you for years. Its pushto system is reliable and accurate. The major negative of the Orion XTi series is that it is not motorized and you will need to manually move the scope to find objects as well as manually move it to keep objects in view of the eyepiece; not something difficult to do but something some people object to doing. Dependent upon the age of your children, this may or may not be a factor in your decision ... but remember ... kids grow fast and generally are able to do more complex tasks than adults give them credit. On the other hand, the lack of a motor drive also gives the XTi series a large positive boost.... lowers its cost and increases its reliability. The XTi is usable when the batteries die or if the mount malfunctions. The goto telescopes in your budget are not.
The 4SE has excellent optics and has many advanced features not with any of the other telescopes including the Orion XTi series. Its mount can be used in either the azimuth mode like all of the other scopes on your list or in the equatorial mode should you ever wish to dap in beginning astrophotography. The telescope has a flip mirror which is useful for photography. The 4SE tripod is rock solid, orders of magnitude better than the tripod on the other telescopes (excluding the Orion XT which does not need a tripod). The 4SE mount can also directly control a digital single lens reflex camera and has other features not on any of the other telescopes you are considering. Whether or not these advanced features are worth anything to you is something only you can decide ...However astronomy is about viewing the heavens. In this regard, the little 4SE can keep its own with the big guys for the moon and planets. It can also compete very well with the brighter deep space objects. For dimmer deep space objects, the two larger scopes on your list will provide better views.
As far as the other telescopes on your list, their goto mounts are reliable and accurate. However, their tripod is weak and shaky detracting from viewing. There are some easy and inexpensive mods that can be done to their tripods to improve the situation but none of them will give the stability of the Orion XTi series or the Celestron SE series telescopes. The shaky tripod makes focusing difficult and also viewing during windy conditions... sort of like loosing an inch of aperture. The little 80 mm telescope is nice but I think that you will be disappointed in the views it gives.
SXINIAS
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Orion ST-80A
Meade 2045LX3
Meade DS2090AT
Celestron NexStar 4 SE
Celestron Advanced Series C6S (XLT), iOptron GOTO Drive
Meade LX200 203mm OTA, SkyWatcher SynScan AZ goto mount
Canon Rebel EOS XS 1000D