Canon G9 with Ikelite DS 51 v DS 125 v other?

I am considering which strobe to get for a Canon G9 with an Ikelite housing. The DS 51 is much cheaper than the DS 125. Is the DS 125 far superior and worth the additional money? What issues/shortcomings would I face using the 51 instead of the 125? Are there any other manufacturer's strobes that are less expensive that would serve me well?

If I were to get the Canon OEM housing with the G9, would anyone recommend a different strobe?

Get the DS-125 with the Ike housing. I've got the -51, but wishing I'd gone with the bigger strobe (so my solution in the near future will be to but a second one).

The -51 is a great strobe for macro stuff, but I've found it just doesn't do what I want for WA stuff.

Wouldn't bother with the Canon housing. With eTTL and being able to add wet lenses to the Ike housing, it makes it a much better investment.