Need advice between twor tweeters for a 3 way system update

Hi -
I am going to update a 3 way system that I built back in 1980. It has an 8" woofer replaced in 2005 due to the foam surround on the original cracking up. Woofer is Dayton RS225S-8. Box is ported for Qts=0.38 driver with fs=27Hz, and is cut over at 1Khz. Not sure of the brand for the mid - It has and fs of about 400Hz, is Ferrofluidic cooled, rolls off starting 5.5Khz. All I recall is that it cost ~ $60 at the time (most expensive part of the system) is stamped "made in Belgium" on it and has no name anywhere else. I originally built the system with a Moto Piezo horn (gasp!) hooked up with an Lpad and a series cap. I would like to update it with something that would have flatter freq response and better dispersion for <~$25 per tweet and was thinking of either:
Vifa 19mm D19TD-05 for about $17 or the Beston Ribbon Tweet RT001A for about $25. I would X over between 4-5Khz
Any advice??
Thanks for the advice Mayhem, I have been looking at both the DX25 and the XT25 for a 2 way that I am planning to build for my Daughter with a 6.5" woofer crossed over at 1.5-2Khz, but my thought was that with the mid and the higher crossover point in this 3 way system I should take advantage of the smallest driver or a ribbon for best angular dispersion. Vifa publishes the 30 and 60degree SPL plots for the D19 but I have not seen it for the XT or DX25 - I found some here: Vifa DX25, and based on a simple figure of merit: dB loss at 60deg at 10Khz (keep in mind I have 53 yr old ears - so I don't weight so heavily the merits of flat response to 30kHz:D) the D19 is down ~5dB, DX25 down ~10db and the XT 25 down 15dB. So - any reason to pick the DX25 over the D19 for this application? (Also - what is HD - harmonic distortion?)