Hi Joe,
It just depends on what you're after. The Vertex Alpha cones are essentially a Bubble King skimmer, built by Royal-Exclusiv (manufacturer of BK), without the Bubble King name on it. This means you're getting the absolute best craftsmanship and build quality available, second to none. Once you see a Royal-Exclusiv built skimmer next to any other brand out there it's evident how much time and quality has gone into the product.
The Alpha skimmers, just like their Bubble King counterparts, are also dead silent. You will not hear them running. You could be setting in your living room, right next to the stand with your doors open and the tv off, you will not hear the skimmer at all. Alpha skimmers, again like the BK skimmers, offer a 10yr part replacement availability guarantee. This means that anytime you would ever need a replacement part 10years from the date of purchase, it's guaranteed to you by Royal-Exclusiv that the part(s) will be available. There really is no other skimmer manufacturer that can claim this.
Performance wise the SRO 5000 Int should be fairly similar to the Alpha 200. You will get less turbulence with the Alpha just by the nature of it being a cone and well balanced with the air / water draw going into the body. The SRO 5000 does have a larger body though, so there is a little more reaction that is going on. For your size system, I don't really see there being a big difference in performance.
If you're wanting the best of the best, go with the Alpha. If you're strictly looking for performance only, and a pretty nice built skimmer for coming from China, the SRO 5000 is a great option for your setup. If you're looking at noise level, keeping the skimmer for years (part replacement availability), and all around craftsmanship and build quality, I would go with the Alpha. Lastly, your budget will play a role as well. Again, the SRO 5000 being a great option for the budget minded!