**Botswana**
You can stay at a lodge in the Okavango Delta. they are usually 3-star and upwards. Another area in Botswana that rivals Okavango is Chobe National Park in the extreme north by Kasane. It is the meeting point of the Chobe River and Zambezi River, and you can add Victoria Falls in Zimbabwe to your package since it is not far off. there are loads of elephants and other Big Five animals.
However, Okavango Delta is unique in the sense that it is vast, as the Kavango River just empties out into the desert. since you are planning for a honeymoon, i guess it could be kind of romantic to take "mokoro" rides along many of the channels, taking in the various wildlife.
"the flood" occurs from June to August but May is good. there is always plenty of water and islands around, and it not being flood season, it would be easier to see more of the wildlife.
The weather in May is pleasant. it will be "Autumn", which basically means it won't be too hot, nor cold at all. The rainy season will be over too.
i don't know much about Namibia except most tourist within the sub-continent visit it for the pure desert experience. Sand dunes provide for fun as well as extreme activities right up to the coast. Namibia also has cheetah sanctuaries as well as Etosha National Park,main feature being a salt pan that has water briefly in the summer attracting flamingos and pelicans.
Source(s):
Life.