I have just started to get into tanking...mainly so I can queue for FP quicker. I have a guardian tank currently (lvl 23) and seem to be doing ok with him (no verbal complaints yet from randoms). My guild is mainly IMP side so I would like to roll a tank on that side. I have been reading all these topics and I am so lost on which class would be a good one to roll. I really do not get alot of the math behind some of this stuff I generally just look up the gear and rotations that I need and do that..with some add in stuff as needed. I have already done the Inquisitor story so if Assassin is close to another I will likely go that way so I do not repeat the same story. I will mainly be doing PVE with some PVP in to just level faster. I play mainly solo but will pick up the occasional guild member or friend but they are generally a DPS style. So, tips advice things I should take into play.....

Assassin? Power Tech? Jugg?

Well, if you've already got a Guardian I'd skip the Juggernaut. It's the same mechanics. And you don't want to redo the Inquisitor story, so scratch the Assassin.

Process of elimination: Power Tech. Added bonus, if you get tired of Shield and PvE just switch to Pyrotech or AP and melt some faces in PvP for a while.