Aeris Manta + Storm Precision 3 Nav/Console - any thoughts on these?

Hi all, I am about to purchase my first dive computer and SPG. I am going to be starting my DM in August in the Bay Islands and I need to get some gear before I go as it's extremely difficult to get mail there and the price is nearly double in the dive shops there.

I have my eye on these:

Aeris Manta - Aeris Manta Dive Watch | Dolphin Scuba Center
Storm Precision 3 Nav/Console - Storm Precision 3 Nav/Console | Dolphin Scuba Center

For the dive computer, I wanted something that could double as a watch (I am a girl so I don't want it to be huge, low-profile is ideal), has user-changeable batteries, and is nitrox capable. My price limit is $450 but would prefer to spend a bit less if I can. I have searched this board and online, and it seems like there is an issue with the batteries in the Manta dying all the time unless you use the Sony batteries. It seems like a good enough first dive computer to me, I really don't need anything fancy. Any further thoughts on this one?

I also had a really hard time finding any reviews of the Storm nav/console...I guess these things are all just pretty standard so no need for reviews? Has anyone here used this, or does it seem like an okay one for a new DM?

Thanks in advance!