Hi Dewang,
I'd recommend a SkyWatcher 80ed, which you could get here for $799:
https://www.bintelshop.com.au/Product.aspx?ID=7290
optically very good, it's also an APO, rather than an Achromat. Should help remove most, if not all of the fringing, etc. Pretty well built, reasonably good quality without spending silly money imho.
and a HEQ5PRO mount, which you can get here for $1699:
https://www.bintelshop.com.au/Product.aspx?ID=7349
Firstly, the HEQ5PRO will take a bit more weight, which will come in handy if you want to put something heavier on the mount. It's also a sturdier mount than the standard HEQ5. It's not too large, nor too heavy, and is easy to assemble.
If you want a larger OTA (optical tube assembly) later on, you don't necessarily have to buy a SCT package - you could just get at SCT OTA and put that on the HEQ5PRO mount! I wouldn't go any larger than 8" though, larger would be too heavy for that mount imho. Some OTAs (Meade) could be had from here:
https://www.bintelshop.com.au/Product.aspx?ID=7163
8", so decent aperture. ACF (advanced coma free) mirror, so pretty good quality optics too. $2300 at the moment. Should be OK on the mount that I recommended.
I've made the suggestions (mount/SCT OTA) because if you want to do astro imaging etc, I honestly think you'll be able to do more with an equatorial mount, than a fork/wedge mount that typically comes with a SCT package. Just mho.
I've also recommended Bintel, rather than Andrews for a variety of reasons. Please PM me if you want to know specifics. Price is not everything, and I don't want to publically get into vendor bashing on IIS.
Dave