Bicycle Mechanics - Upgrading Older Touring Bike

I have an older Lotus 3000R touring bike, I love this bike, but the problem I have is the it only has dual crank, 170mm , 52 and 42. So I am dying when I climb hills.
So I am thinking of upgrading to triple crank, but I found two that I am thinking of getting.
First one is 170mm, 52 , 42 and 30
Second one is 175mm, 53 , 40 and 30
I am not sure which one is a better choice. I would like to get some advice on pros and cons of the cranks I have described.
Thanks

There is a great gear calculator on Sheldon Brown's website.
What you have on the rear is just as important as what's up front.
Enjoy

Assuming your rear derailleur will handle it, I'd just switch to larger cogwheels at the rear. It should be cheaper than replacing your crankset. You might also consider just switching out your 42 tooth front chainring to a smaller one if the spider on your current cranks will handle it.

The choice between 170 and 175 depends maily on your leg length. If you are above abouy 6' tall, then 175 may better suited to your legs.
Work out the highest gear you currently need (in gear inches). There is no need to go higher. I have used a 30/40/50 and a 28/38/48. There are a few times I have wanted lower gears but I have never needed higher. Exactly what gearing you need depends on your strength, the terrain and your load.

Michael has the right idea. 48 or 50 teeth should be PLENTY for your largest chainring. You do not even have to go to a triple, since a double with a 110mm BCD can accommodate a combination such as 48-34, which should work well in your application, with your existing derailleurs and perhaps even your bottom bracket.

In the 110/74 mm pattern, you could get a Sugino crankset. There is a basic modelthat comes for $70-80 (CDN) and that already has 46-36-26 rings. For the same price or a few dollars more you could ask the shop to replace the 26 with a 24.

if your going to do loaded touring imo you need the triple. If not I would not worry about it.