EQ-6, EQ-6R (or the Orion Atlas, rebranded EQ6 in U.S.) are the budget mounts I would suggest. The R is better , belt drives make is quiet, but I've been using my EQ-6 for 5 years with very good results. My EQ6 did require me to tune out the worm gears and thrust bearings which meant some reading and some tweaking and a special tool. My buddy's R ran superb out the box at a higher cost. Do not buy a used Orion version of these (Atlas, Atlas Pro) as they will not support them unless your the 1st owner. Not sure what the Skywatcher service rules are. You can run them from your computer via EQMOD software. Its an decent solution, not as good as a native ASCOM driver found on other mounts, but its it mature, reliable and complete. These mounts work with almost all the software you will need and there are many Apps that are free to really cheap to get you started. EQMOD-Free, BYEOS(cheap), APT(cheap), SGPro (moderate cost), plus Plate Solvers. If I had the budget years ago and the knowledge I'd gone with a Mach1, now Mach2, but 3x Cost of the EQ6's. I would not recommend a Paramount to a beginner. My buddies have had them, The SkyX is daunting, they have not been bullet proof electronically, they need some annual service. The Celestron's are very good, a friend runs a CGX and its quite a beast and generally likes it. Though I've heard him cussing its guiding accuracy occasionally. That said, I cuss at mine sometimes also. There are more options than ever but depending on how important the budget is in the end I say a new EQ6R if you can afford it, if not a new EQ6 will give you years of service and will get you to the next level when your ready.
Jeff