Tips for backpacking SE Asia with camera

Hi,

I'm planning a backpacking trip to Southeast Asia, probably for 5-6 weeks in spring next year. Of course I want to take pictures, and I am planning my next investments having this trip in mind.

There are three points I am not sure about and I'd like to know your opininion.

First of all, my kit. I've got a K-r and a Tamron 17-50 f/2.8. This will constitute the core of my setup for the trip. As a backup I could add my kit 17-55, which I rarely use.

I am thinking about investing in a DA 55-300 or a Flash to complete my setup... but then, I might feel uncomfortable carrying a too valuable kit, and the camera bag shouldn't get too heavy. I'm not sure how much use I would have for either of them.

I know that this is highly subjective, but what would you do? I can't afford both or more expensive gear by the way.

Second, do you think the hot and humid climate will cause any problems for my gear?

Finally, data management and backup. I shoot RAW, I roughly estimate my pictures will sum up to something like 1 GB each day. What do I do with all these files? I certainly don't want to risk losing them. But convenience is important as well and I don't want to carry a laptop, nor do I want to spend a substantial part of my holiday searching for internet cafes and waiting for slow uploads to finish.

So I'm thinking about getting 6 SD cards with 8 GB each and a Nexto Extreme 500 GB:

http://www.amazon.co.uk/NextoDI-Nexto-Extreme-ND2700-ND-2700/dp/B002PTUP2C/ref=sr_1_1?ie=UTF8&qid=1303391757&sr=1-1

I would leave all the pictures on SD cards and carry them in my camera bag. In the evening, I would copy them to the Nexto, which stays in the hostel or hotel whenever I go out.

What do you think about this backup strategy - do you have any ideas how to do it more cheaply or in a more reliable way?

Thanks in advance,
Johann

I don't want to post a long text only - so here is, totally out of context, a bass player from Portobello Road: