Welcome from a fellow dual Star fan
To keep the cost of your 'trainer' hilt down, it's best to consider what options deliver the most effective bang for your buck.
The li-ion batteries are very good for delivering a consistent charge from 100% to 0%, so your blade will look as bright as can be until the power dies completely. Is that massively important to you? If not, go with the standard setup (4xAAA) and get a couple of sets of rechargeables.
The cheaper hilts are
generally the most comfortable to wield - they tend to be lighter and simpler in form, so you can move your hands around more freely and can usually mind more places to grip comfortably. There are exceptions, but for a sparring blade, I find that cheap is cheerful
The one optional extra I tend to favour on a stunt 'sabre is the AV switch. It has a lower profile and the bezel has rounded edges, meaning if you grab that part of the 'sabre during combat, it'll be less intrusive and distracting in your hand. It's a minor thing, but I personally think they look better as well. I believe it's a $15 premium, and in my opinion worth having.
While the Prophecy is a very comfortable hilt to wield, especially one handed, it's on the fussier end of the scale. If you like the look of it, I can certainly recommend it with the minor caveat that the accent knobs on the emitter can come loose during a duel. Doesn't take but a second to adjust them, but over time they could come off, leaving the screws underneath exposed. You may be able to glue them to the screws, or replace them with actual thumbscrews, or may find it's not an issue, but on each of mine it's something I've noticed.
My personal preference for simple sparring 'sabres are either:
1. Aeon/Dominix v2 (or the shorter Initiate/Dark Initiate v2), which are lightweight and have a slender grip, but which aren't compatible with the li-ion setup, sound or Emerald, or;
2. Sentinel/Dark Sentinel (or the shorter Apprentice/Dark Apprentice), which are lightweight with varied grip points, MHS compatible at the pommel end and can have any combination of li-ion batteries with or without either sound or Emerald installed.
Hope that helps - let me know if you have any questions. I've handled most of the US lineup in some form or another, so can offer some reasonable comparisons.
