8ohms vs 4ohm the great debate.
Are you planning to go Active or useing a Passive x-over??
I think the LPG are great tweeters.
Lookat JL audio, Diamond which uses LPG.
The Seas tweeter are great for the price, but they need to have steep slope.
The SB Acoustics neo are a great sounding tweeter as well, but they seem to have problems in the heat.
The LPG are great, but need to be EQed to tame them down.
Have you looked at the NE Vifa tweeters?
I think Vifa makes one best open airy top end tweeters for a great price.