The lavatube your getting is the older one with a 2.5 amp limit. Like someone else said, dual coil cartos really don't work very well on the 2.5 amp lavatube. I would get single coil cartos bc the lavatube will run them a lot better.
I wouldn't get either of the cartos you posted links to. The ones from vaporgod are the replacement cartos for the Smoktech tanks, but they are the 1.5ohm ones. Using them would basically defeat the purpose of having variable voltage. 1.5ohm is very low and you would only be able to vaPe at around 3.7v and couldn't crank up the voltage at all.
The second link cartos are a higher ohm, but they are still dual coils, which don't work well with the 2.5 amp lavatube like stated before. Also they are black so you'd have to peel off the sticker and then use something like goof-off to get the sticky stuff off the tube.
What PG/VG ratio are the juices you use? The reason I ask is bc the Smoktech replacement cartos for the tanks do work well; but the pre-punched hole is small. If your using thin PG juices than your fine, but if you use thicker VG juices you'd most likely have to punch the hole bigger. Doing that's not a big deal though. I have a Smoktech tank and the juIce I use is thick. I just use a finishing nail and hammer and punch them all bigger before I use them and then they work fine with thicker VG juices.
The Smoktech pre-punched cartos are nice bc they have a flanged bottom and are made to be used in the Smoktech tanks. The flanged bottom stops the tanks from being able to slide down.
Smoktech has both dual coil and single coil pre-punched cartos with the flanged bottom for the Smoktech tanks. For the dual coil ones they have 1.25ohm, 1.5ohm, 2.0ohm, 2.5ohm, and 3.0ohm. The single coil ones they have are 1.7ohm, 2.0ohm, 3.0ohm, and 5.0ohm.
Since dual coils don't work well on the lavatube, you shouldn't get any of the dual coil pre-punched cartos. The single coil ones though will work well on your lavatube and in your tank though. If you want to be able to use the widest range of voltages you should get the 3.0ohm single coil pre-punched cartos. The 1.7ohm and 2.0ohm ones won't allow you to put the voltage much past around 4.5V, but with the 3.0ohm ones you would be able too.
I have a SS mini lavatube and also have a few Smoktech tanks too. I use the 3.0ohm single coil pre-punched cartos in my tanks and they work awesome on the lavatube. With the 3.0ohm ones you can use the full range of voltages, around 3.7V-4.2V if you want a cooler vape, or you could crank it up to 5-6V if you want a nice warm vape with more TH.
Madvapes sells the 3.0ohm single coil pre-punched cartos and that's where i got mine. They are sold out of them right now, but should have more soon if you decide to get them. I'm not sure if they ship to Canada or not so you'd have to ask, but here's the link to them :
Tank Replacement Single Coil Cartomizers, 3.0 ohms, single hole
Hope this helps