In your instance, the best option appears to be to stick with the Jackson Elite: (1) your previous experience with them were good, (2) you know your size, and (3) you don’t have access to a competent fitter. Jackson has instructional videos on their website. One of them is on fitting. It specifically states that the advanced Jackson boots are fitted on split lasts, with the heel one width narrower than the toe: for example, a D width across the toes is mated to a C width across the heel. I too have a narrow heel: for about the past year I have been skating with men’s Jackson Elite suede (model numbers for men’s line are different from those for women’s line; this model is one down from their top-of-the-line Elite Supreme); I’ve been very happy with the fit.
The widths are only two (out of many) parameters that determine whether the boot is the proper mate for you. Even if another model has the same widths you need, you may require a longer transition period if you switch. My previous boot was an old pair of Riedell Royals. The Royals were a 9N; the Elites are a 8W; consequently, the blade length went from an 11” to a 10-1/2”, and I had to retune my moves. The Royals had a high arch support; the Elites have none; consequently, I had to add arch supports to the Elites. The Elites have a much higher heel than the Royals; consequently, I had to re-learn my back edges. When I first switched to the Elites, I tended to rise up on my toes when skating backwards (but, curiously, no problems when skating forwards); consequently, I had to lean further back. My skate tech told me this was typical. He also mentioned in passing that the Ice Fly has an even higher heel pitch than the Elite: it’s not obvious from looking at the exterior of the boot, the heel is further raised inside the boot of the Ice Fly. So, if you want minimal disruption to your routines, replace what you have, if you are otherwise happy with them.