Hi. I am building my own 2 x10" bass cab and used the WinISD programme to design it. I am using 2 x Celestion BN10-300X watts speakers at 8ohms each wired in parallel making the cab  600 watts in total at 4 ohms. My question is, What compression tweeter and crossover unit should I put in my cab to match? Do I need to buy a tweeter that is rated 4 ohms and 600 watts? The same question with the crossover unit. I see a lot of tweeters and crossover units on the market that all seem to be rated at 8