I like both, the Classic and the Shiva. Splawns are great but sound very 80s metal (at least on all the clips I heard so far).
Also keep in mind that an amp like the Shiva will give you not only an awesome distorted tone, but also the most amazing clean sound, really 3D, dynamic, punchy and "nice to the ear".
Indeed the Classic is awfully expensive.
It's hard to test any Splawns in Europe, there are no dealers that stock them.
If I were you I'd try as many amps as I can and decide based on that experience. If a certain amp make like Splawn, Mojave, Roccaforte etc. isn't available for testing, don't think about it. You don't wanna spend more than 1,000 GBP on something you haven't verified.
My own decision making process included testing several Mesas, Soldanos, Diezels, Engls, Bogners, VHTs, Kochs, Marshalls, Randall (wanted to try the Egnater too, but was a 450KM drive that I didn't wanna do for it).
Don't hurry it and only put the money on the desk once you're absolutely sure you are in "last amp ever" territory.
You don't wanna arrive home and hear the amp first time in your accustomed environment realising that you just can't get it to sound perfect ...