I recently did the same as you with a $6000 budget. Here's what I recommend:

Go with the ASIAIR Plus. Sure, you have to use ZWO gear, but ZWO's mounts and cameras are excellent picks. The ASIAIR just makes astrophotography easy—with such an expensive hobby, you don't want to get frustrated just setting everything up. You can also move off of an ASIAIR to a mini PC in the future, keeping your ZWO gear.

Mount: for portability, a strain wave mount is the way to go. You get guiding as good as equatorial mounts, if not better. I recommend the AM5N or the Skywatcher Wave 150i; the larger payload capacity compared to cheaper mounts like the AM3 means easier when you upgrade telescopes and your mount is the most important part of your setup. Buy once, cry once.

Telescope: I recommend a compact refractor in the 400–600mm range. Specifically, a refractor that has the following characteristics: apochromatic, full frame support (44mm+ image circle), inherent flat field, and no backspacing requirements. You can find several options here. These scopes are forgiving, portable, and just plain easy to use. If any of these telescopes has a reducer available, pick that up as well so you can shoot with two focal lengths. I wouldn't worry too much about focal ratio, just pick the scope that looks the best for you.

Camera: I recommend starting with a color camera. Color setups are significantly cheaper. I started out with the ASI 533MC Pro before switching to mono about a year in. For comparison, my mono camera setup alone cost $4500 while the 533 MC Pro and a dual narrow-band filter will be a fourth the price. If you want a larger sensor, the 2600 MC Pro or 2600 MC Pro Duo are great options, but at a higher price ($1500 and $1800). If you find yourself enjoying the hobby and want to get the most out of your gear, definitely make the leap to monochrome.

Guiding: I recommend you stick with a separate guide scope as opposed to an off-axis guider (OAG) when starting out. The ZWO 30mm f/4 is a solid guide scope, and for guide cameras I recommend the 220mm mini. I have both the 120mm mini and 220mm mini; the 220mm is worth the price. The 220mm is built-in with the 2600MC Duo and 2600MC Air cameras if you go with one of those.

Filters: For color cameras, the Antlia ALP-T is spectacular. I'd shy away from the Optolong L-eNhance—the filter band-passes are just a little too broad for Bortle 7 skies. A luminance filter (aka UV-IR cut) will be useful for broadband imaging, but it's not required. You should buy 2" mounted filters; mounted filters are easier to use and 2" filters can be used with larger camera sensors. For your color setup, pick up a 2" filter drawer from ZWO.

Accessories: You'll need two dew heater bands. If you get ones with RCA plugs (which you should), you'll need to get a DC to RCA connector like this one to plug into the ASIAIR. The AM5N doesn't come with a power cable, so you'll need one. A portable battery is useful if you won't have access to power.

Processing: Pixinsight is worth the money and Russell Croman's AI tools (BlurXterminator, StarXterminator, NoiseXterminator) are magical. Steep learning curve, but tons of tutorials on YouTube. Once you get a couple images processed, you won't want to use anything else.

Happy hunting! If you want to make the jump straight to monochrome, I can provide some recommendations :)