I've just finished researching and buying a set of doubles and a wing; I feel your pain! The information one can get on the internet is incredibly biased and is based on a poster's geographic location, type of diving, air consumption, fills and mixes available.
It is important to talk to the divers doing the diving you want to do in the area you want to do it.
For me, PNW cold water deco dives with less than 30 minutes of deco, in a dry suit, one deco gas, led me to HP 100s. I'm not afraid of the weight of the bigger tanks, despite being 5'8", but I did want a doubles set that I could and would dive all the time to get bottom time in the rig on lots of recreational shore dives prior to fundies/tech training. If I ever get to bigger, badder dives, I'll get 130s. No big deal. If I move to cave country to do huge penetrations I'll get what works there, LP 104s or whatever is gospel. Getting trimix fills is easy here: there are boosters around, I can get partial pressure blends, 32% is banked for "standard" trimix mixes. If that's not the case where you are maybe LP tanks make it easier to get the right mixes, I don't know. Again, that's why you need to talk with divers doing your dives in your area. Good luck!
VI