The divers in the above refrenced video appear to be using lp 85's / hp 100's. That is a small steel tank by Florida standards. Show me a video of the Stealth / Razor with Lp 108's / 120's and multiple stages. The Stealth / Razor are not designed for that and that is a fairly common North Florida cave dive.
Hmm...a couple of ways to go with this.
Let's start out by saying the OP is from Singapore, is going to Coz, Bonaire, Roatan and Belize. I'm not sure what his chances are of renting Lp108's/120s are in those locations. And I don't think he'll be hauling tanks to all those locations. Like I said, there's a whole other world out there besides Florida.
The link I gave was of tourist divers going to Florida, renting steel tanks and doing a cave dive in Florida. Ginnie Springs is a fairly common cave dive for those visiting Florida.
I think it was Victor who stated in another thread that lp 85s are the tanks that Edd recommends for sidemount diving.
I don't believe Worthington is producing scuba tanks anymore, so Fabers are pretty much the way to go now for steels. I've had no issues diving them in my Stealth.
I won't be able to show you videos of Razor/Stealth with 108/120s with multiple stages in your Florida caves because you've already said that people don't do that in Florida.
Can we go the other way and can you please post video of your sidemount dives in 108/120s with multiple stages? I'm always open to learning and seeing other ways of doing things. Heck, I'm still signing up for courses. So I genuinely would appreciate seeing how you do it. I'm having problems seeing how you would mount the stages in a streamlined manner using the buttplate. I'm not a fan of the video Lamar has showing the "Edd" technique of mounting stages. I like, and use, the staging technique that Bogaerts uses in his videos. But, like I said, I'm open to learning.
Take your heavy 108s/120s and try going through some of the sidemount only caves in Mexico without damaging anything. My take is that it would be very difficult. That wouldn't be the ideal set up for a dive requiring finesse in my opinion.