The question that will best lead you to an answer is:
Why do you want/need a diving light?
If you are using/plan to use a diving light for infrequent night dives/technical dives and mainly do "recreational" daylight dives, then a cannister light while a very nice piece of equipment and would be a dream to use, is overkill if you have other pieces of gear that you are looking to upgrade (you mentioned a new APEKS reg you wanted?). I'd just rent a cannister light for those occasions.
If you currently do or soon plan to go on night dives/technical dives semi-frequently then saving for/getting a cannister light is a great way to go.
If you are short on cash in the near term, you don't need to blow $1k on a Halcyon Helios system, you can find Halcyon Proteus lights with HID heads for ~$600 new, and a few hundred cheaper used (e.g. there was a 10 watt Halcyon HID on ebay for $400 earlier today). You just have to put up with a larger lead acid cannisters for similar run times to the NiMH systems, and in a few years when you are more flush, can swap out the cannister for a newer one of whatever flavour of battery technology is out at that time. Or you can go with some of the less pricey Halcyon cannister light competition, many of whom make functional and more than adaquate light systems.
Buying the best gear that suits your diving does not always mean buying the "best of the breed" in all circumstances.