Hunting with my son this season and came to the realization that my gun is not set up for low light situations.

My eyes are not bad, but they are not great either.

I am running a Marlin Guide gun with a scout scope mount on it.

The black cross hairs in low light just will not do it.

Recommendations on a red dot for my Marlins?

H-1 Micro from the good folks over at Aimpoint. That's the only company that I'd trust my life to when it comes to red dots, as I have multiple times, home and Abroad.

I love aimpoints. Cost effective, bulletproof and effective.

Aimpoint micro is the only way to go.

I have a Leopold vxr pigplex on my socom.  It would also work well for a lever gun.  Gives the best of both worlds, l
A little magnification and a red dot.

You can't go wrong with any Aimpoint product, but if ultra-light weight and compact size are not issues (you didn't specify the nature of your hunt, leaving  us to guess your requirements...) you may want to consider the Aimpoint "PRO" ---Patrol Rifle Optic  ---  a rugged but not especially lightweight or small  unit, offered at a significantly lower price than the Micro model, and if longer ranges may be involved, some Aimpoint models have been offered with 2 MOA dots and 2X magnification, offering a little extra aiming edge at extended ranges. I have a 9000SC on a Contender Super 14 in .223, and a Comp C3 on a bullpup .223,both 2MOA/2X , and find them ideal for any use from powder burn range to 200 yards, and beyond,with the carbine. There is a lot of cheap, red-dot knock-off junk on the market, much of which, I suspect, will succumb, at an inopportune instant, to the heavy recoil of your Guide Gun. Since you didn't specify your hunting technique, but referred only to low light level shooting conditions, I'm assuming that you are looking forward to shooting a bear lured to a bait station, from a tree stand or blind of some sort, for which any Aimpoint will serve.

I'm curious as to which Aimpoint has a 2x capability?

I don't know, and can't say, about current offerings. The models I mentioned, and perhaps others, were offered in the 2MOA/2X configuration, and I'd be surprised if others weren't offered as well --- I seem to recall that the 7000SC once mounted on my Contender had the same configuration. I am considering retiring my Contender rig, so, if you're interested in a very-little used TC  Contender,
stainless, with .223 Super 14 barrel in .223 with MuzzleTamer  brake, or, the Aimpoint 9000SC 2MOA/2X optic, send a message...

2x Aimpoint. Discontinued a few years ago

http://www.aimpoint.com/us/products/discontinued-sights/product-singleview/product/CompML2%202X/

I have a Zeiss red dot on my .44 Mag, the Leopold scope on my guide gun has a Illuminated dot Reticle, and the Marlin 336 in .35 Rem has a Burris Illuminated  Reticle.  Make a big difference in low light for any target 2 or 4 legged.