I personally found that getting PVP cent gear was much easier than anything else, so I went with that. you used to get a full set in a week doing ilum daily and weekly but you cant atm. However, if you have wz commendations now, you should be able to get the pvp gear at around the same time.
Once you have pvp, its just a matter or running the low HMs and 8 man normal ops as much as possible.
FPs not are not locked, you can can do BT multiple times with different people till everyone gets a columi bracers.
Then run Foundry, Apart from HK, it should be nice. HK drops tionese weapon and revan drops Columi boots. once again run with multiple groups as many times as you can to get everyone geared. This will give you enough commendations+crystals for 2-3 tionese items too.
Other ones I would suggest is BP, and FE, they drop GLOVES and chest. if you get enough columi commendations, buy you pants asap. coz D7 HM is feked.
ops are really great, they get a lot more ppl geared more quickly, and are much more fun imo. You need to know fights so study vids, get a vent or mumble server.
Once you get the hand of ops and a few more columi pieces, run HM OPS.
I wish people would stop promoting the idea of getting pvp gear in order to do pve content, its completely unnecessary (and now even worse an idea with recruit set being vastly under-par for PvE content).
To start running HM FPs you just need orange gear full of Blue/purple L49/50 mods. If all of your group are starting HMs at the same time, it might be worthwhile spending some extra time on the ilum/belsavis dailies to make sure you're all well kitted out in the armour/mod/enhancements... doesnt take too long though because you can buy L50 purple barrels/armourings for 8 dailies a piece, and the heroic quests drop mods/enhancements.. your gear up shouldn't take long.
As suggested, probably start with BT first, its generally quick and easy. Move on to BP, Foundry, FE and kaon isn't that hard once you get the hang of knowing what to do with the trash mobs. D7 is a bit more tricky though, but still perfectly doable.
End bosses drop tokens for columi gear as follows: BT - bracers; BP - gloves; Foundry - boots; FE - Chest; Kaon - head; BoI - offhand; D7 - legs. Those are a great step up in gear and will make the stuff easier to run. Through the HMs you will also pick up tionese commendations and crystals, which you can use to purchase stuff from the tionese vendor. These are great filler items before you get full columi, as they contribute to the set bonus along with the columi items.
Once you've got a bit of columi/tionese, you can also walk into the normal mode operations, for more columi drops + tionese crystals.