I was going to recommend a 800mw Jetlasers myself, but based upon the visual brilliance alone, the difference between a 600mw and a 800mw Jetlasers isn't that much, in my view not worth buying another one unless perhaps you sell your old one and add the money together to buy a higher power version. The Jetlasers can do 800mw, but as all DPSS pointers I've owned are, they are temperature sensitive and will drift around in power from start to finish when using them as they warm up, so even the 800mw version can dip down to 400mw if they get too warm, then you must allow them to cool off some before using again for full power output, at least, this is how my Jetlasers 800mw pointer behaves and probably one of the reasons you want the higher power version, as your 600mw Jetlasers probably dips down to 300mw when it gets too warm. In Alaska where I am at, I can have the opposite problem, mine won't produce full output because it is too cold!
Perhaps consider a NDG7475T based 520nm laser which isn't so temperature sensitive? Only thing is, I don't like the divergence of multimode diodes and won't have one myself without a beam expander on it, then you have a very fat beam though. One thing though, the NDG7475T can put out 1.4 watts in most cases, sometimes more, but even though 520nm which our eyes are a little less sensitive to, that will be far brighter than a 800mw 532nm laser, except for power density, due to having a much wider beam, of course. When pointing into the night sky with a beam expander on a 1.4 watt 520nm laser pointer, my own setup like this is far more satisfying than a 800mw Jetlasers as far as brightness. Only thing is, with the 520nm 1.4w watt laser and beam expander you probably won't find the quality you get with a Jetlasers host, are they going to offer a 1.4 watt 520nm version of their host someday, anyone know?
Here's what I found on their web site for 1 watt of 520nm which is as bright as 800mw of 532nm, but it appears to be fixed focus and they mention something about it being single mode, I guarantee it isn't singe mode at 1 watt, that only applies to their lower power versions, I am sure.
http://jetlasers.org/equality-series/25-520nm-equality-series-green-lasers-diode-laser.html
If this is threaded to allow the use of their 10X beam expander, I think it might be something to consider, the price is right but I don't think it will accept their beam expander, they don't show it in their drop down options menu. I think the reason they don't offer their standard beam expander used on their 532nm DPSS laser is probably due to their 520nm laser pointers larger 3mm beam width, at that size of a beam a 10X beam expander will require a output lens which is at least, if not more than 30mm diameter and the expander used on their 532nm laser pointer has a diameter of only 25mm, if I remember right. You could probably get away with using their 25mm output diameter 10X expander on pointer with a 3mm wide beam output, but some of the output power will be cut off or lost. However, I doubt they will have the needed threads on their 520nm laser pointers to attach their beam expander, since I don't think they designed it for that. That said, Sinner designed a Jetlasers adapter to be used on one of his hosts with multimode laser diodes and he says it works great, maybe it doesn't really cut so much of the power off of a 3mm wide beam output to be so concerned over.
I never intended my response to get this long
