Well from what I understand a terrarium is all plants and a vivarium is basically a terrarium with animals in it =) I might be wrong....but Im sure if I am someone will correct me, ignorant???? unless your rude and uneducated, which Im sure your not! LOL! you just need info thats all, we all started like you, but let me warn you, the site has been very slow lately so please hang in there, if you or your wife do not like the "singing" of frogs then they are out of the question, I myself love the song of the coqui, they sung me to sleep many a night,29 G is fine, and the money you put into it is up to you, you can have a simple set up or a very complicated one, its totally up to you, as for web sites and books...well, the only place I REALLY like is this one, http://www.wildsky.net/vivarium/evivariu.htm
Jun has a great amount of set ups by both beginners and experts, take a hop on over and check him out, if you do a search at the bottom of the page you will also find post on just about any question you might have, so go on and take a look at both this site and wildsky, then ask any question you we/Jun might have missed =) Good Luck and please come back often =)

Hello!
Wow! I don't believe it but someone actually posted a thread here in this forum!!! I have been wondering if it is just that everyone is so busy just trying to keep the terrariums alive or their own worlds alive and don't have any time or any issues to deal with!!

However I would like to recommend a couple of things.
1. Forget the frogs but you can try newts!
Or you could try anoeles!
These can be obtained from The Carolina Biological Supply House online. It is a huge site and takes a while to download else I would attempt a direct link to the living specimens-animals section.
With newts you could insert a plastic storage box into the aquarium and fill the aquarium with water up to or even slightly above the top of the box. You can plant the box with aquatic plants or what are called marginals but you would have to use the smaller species that would work.
Also you may want to improve the lighting on your aquarium with full-spectrum bulbs. Basically the construction of a planting bed from the bottom is: coarse gravel topped by activated charcoal topped by a filter mat or something that is porous but will keep soil out of the charcoal then topped by potting soil in which are planted the plants and the space between filled with a surfacing of woodsy substrate for amphibians (available at pet shops) or tropical moss (available online). You could even add an aquatic plant that grows out of the water. Lots to choose from.
With anoeles you can dispense with any water as they drink water droplets. set up your planting base as above but you can use plants that are not aquatic and for a first time use I would just check out the inexpensive house plants at WalMart and try any just to see how they do for you as these are easily replaceable and won't cost you an arm and a leg! Again check out the lighting.
The only other thing you would need to consider is food for the animals and that should be available at the Biological House or from whereever you buy the animals-check locally first before online ordering.
If you opt out of a vivarium for a terrarium then maybe you can surprise your wife and clean the entire aquarium out and get some potted African Violets and just set them in pot and all. Again check for full spectrum light bulbs.
All you would need do is google for how to care for African Violets. (This last one is what I am been planning for awhile with an old aquarium too but time is hard to find to do so!!)
Hope all this helps.
I would recommend checking out all the different
terrarium
vivarium
herp
sites using google and even sites on anoeles and newt or efts.
Enjoy.