Do you have a multimeter? Since you will be pulling the tweeters anyway checking the DCR of the tweets gives a data point. Results of the tweeters DCR measurements can yield clues to what might have happened.

You have a spare tweeter in the third speaker, have you tried swapping it in place of one of the non working drivers?

From what you have posted I would tend to agree with Ben's diagnosis of an overdriven amp. While more power can yield greater headroom please remember that every 3db increase in spl requires double the power output from the amplifier. In your case going from 160 watts to 300 watts will yield slightly less than a 3db increase in spl.

Do your speakers have any type of hf driver protection? Are they fused or contain a polyswitch? I am not trying to rain on your parade here but based on your own comments it would seem you are at least partially responsible for the driver failures.

How do you have the 2150 set up related to eq, tone controls, and sub crossover?

If all you are interested in hearing are amp recommendations pay attention the the pre out voltage of the 2150 and input sensitivity of any amplifier you might consider. Output/Input variances can lead to over or under driven conditions.

An idea of budget is needed to make any suggestions. If your primary requirement is raw power the Crown PA amps provide big power for the buck and can be had dirt cheap on the used market. I do not like pro amps for home other than running subs use while others feel they are fine. YMMV