The only advantages I can see of the Clarion are a slightly lower price and a marginally higher continuous power rating. The fact that it will tolerate a lower impedance could be considered an advantage if you think you might want to add more speakers at a later date but frankly, I wouldn't factor that in.
The Alpine is capable of bridging channels but again not an especially relevant feature in your build, I think. Personally I think I'd err on the side of the Alpine but that's partly for brand name reasons, and partly because bridging channels in the future seems ever so slightly more likely than needing 2 ohm impedance for wiring in parallel, but it's a really marginal call. Do some googling and see what the criticisms of each one are.