Which Amp and Cabs? I can't make a decision.

I think that the ABM600 Evo IV is the best sounding, readily available solid state amp Ashdown has made to date.

 

I assume the question has to do with not being able to try things out first, to see what YOU like best.
Of course Sparky Mark's (cool name) opinion of good, and my opinion of good, may not align with yours.
If you go through a reputable dealer, with a good return policy, you can feel better about rolling the dice (or flipping a three headed coin) and if you hate it, return it and try something else.

Hey Sparky Mark... [entity of your choice] Save the King. The Queen will be missed.

 

What is your goal?

If you need a lot of firepower, stay focused (IMHO) on the 15" cab pairs, and take the 300 watt amp off the short list.

If you're not in need of "really loud" anything you've listed there is a great choice.

 

You have the right idea about two cabinets. As to how much firepower you actually need: get more than you are used to. Two vertically stacked 210's are a great choice. Two 15's can also be awesome. What bass stores are nearby where you can try gear out with YOUR bass? Time for a road trip!

Guitar Center Used gear - potential good deals with a return policy. Look into it! You will only be out the shipping cost (15-$30 typically) if you return anything.

Some stages are going to eat up your bass tone and you will be glad you have more firepower behind you. Or it will be so loud on stage from the PA system that you will need more firepower behind you to hear what you are playing. Again, more firepower is always a helpful thing and if you have too much, you can always unplug one cabinet. For years, I rocked two 410's or two 210's. For stage monitoring, the vertical 210's were fantastic. For shows in small rooms with no PA support for instruments, the two 410's were a great fit.