Celestion Ditton 66 Amplifier?

I have an old pair of Ditton 66's I have recently refurbished that I bought new in 1980. My problem is I have gone through about 5 amps searching for one that is capable iof driving these beasts properly. I'd like to find an AMP or AMP/PREamp that will hopefully cost less than $1000.

I don't care if it's old or new. I just need something to unleash these monsters. For those in the know, these are 4 ohm speakers that are extremely inefficient.

Does anyone have experience with Ditton 66's, enough to provide a recommendation???