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In general terms, Alt/Az Goto/tracking mounts in any form are only suitable for short exposure shots when imaging deep sky objects.
You will need to experiment with your exposure lengths to see how far you can push before you get star trails. 20 seconds would be around the upper limit from my experience.
With respect to planetary/lunar imaging, Alt/Az Goto/tracking mounts are fine, generally one captures around 30 seconds of video which results in over a 1000 frames for quality selection & subsequent stacking. Since you are entirely focused on the planet & not the surrounding stars, this method provides adequate tracking to capture some stunning planetary & lunar images.
For long exposure AP you will need an Equatorial mount, this is because an equatorial mount is setup to take into account the earth axis tilt; ie: your mount will track perfectly (well, depending on how well setup it is & how good the mount is) in line with the earth's rotation axis. Some Alt/Az setups allow for the addition of an Equatorial Wedge, this essentially converts your Alt/Az setup to an EQ setup with the wedge being setup to an angle that corresponds with the earth's equatorial axis, ie: your latitude.
Even with an Equatorial mount, exposures are generally limited to around 2 minutes or under unless you add guiding into the mix. There are exceptions to this but, you will pay a lot of money to purchase a mount capable of doing over 2 minutes unguided & it will still depend on how well you set it up to achieve this.
To accomodate your 10" f5 tube you would be looking at an EQ6 as a minimum.
Hope this helps with your decision making process
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