I won't go on about the plan I have, as I'm sure I've mentioned it quite recently and I don't want to come across as trying to promote any one plan or company. Instead, I just want to make a few comments, which will hopefully help you:
A) You know what you want out of your health cover. Keep matching the products you're looking at against your "shopping list" and you'll find it a bit easier. Don't get too bogged down in the extra bells and whistles, but do consider them if all other things are equal in your final choices.
2) You're correct in saying that you could have two different plans. You on the more basic of the two and your partner on the plan with the better cover for cardiac and maternity. You could even have them with two different insurers.
3) Another option to consider is that you could have your hospital cover and your GP (out-patient cover) as seperate policies, again even possibly from different insurers. E.g. HealthSteps from VHI or day to day from Aviva. This does give you more options (and possibly, more confusion), but it is an option in case the "all in one" packages aren't giving you exactly what you want.
4) This is something I've said before, but before you sign anything, ask your chosen insurer if they have a Company/Corporate version of the plan you've decided upon. I'm on a company product myself, which is more than €100 cheaper than the "mainstream" equivalent. Under Open enrolment, you can't be refused cover on any product, so if the company plan offers the same benefit as the one you've chosen, you should go for it.