My suggestion is to first grind either Vanguard or Crucible rep to at least Rank 2. At that Rank, for either faction, you can buy a full set of Leg armor with Marks. Really comes down to which part of the game you like the least - PvP or PvE - and do the opposite. Quickest way to Vanguard grind is to always grab Vanguard bounties, farm missions on Patrol (usually just the Kill These Guys, Collect X from Those Guys and Kill This Major are the best to do as they're quicker and net you additional rewards, along with giving you more Rep and Marks) and do Strikes in the Vanguard Playlist at your level; the Playlist Tiger Strikes would be the fastest route and does offer Matchmaking so you can grind whenever you're able. Crucible rep might be a bit more of a slog; grab bounties always and just play PvP like mad. Clash and Skirmish are good because the matches don't last as long as Control or Rumble. You get 25 rep and 3 Marks for a win and 10 rep and 2 Marks for a loss. This is the path I took for grinding; wasn't too terribly long, even with a sporadic play schedule. After you hit Rank 2 with either, I would suggest continuing the grind to Rank 3; that's when you open up being able to buy Leg weapons. Vanguard and Crucible factions are very good as they offer at least 1, sometimes 2, of every weapon in the game - primaries, secondaries and heavies - so you have some choice. I know that the Hand Cannons either offer are very, very good; I've not yet bought one as I got Timur's Lash to drop, but plan on getting Lord High Fixer to replace it as it's superior in a lot of ways. But there are some very, very good weapons available from each that can last you until you're able to snag a better Exo. Once you max with one of these two factions, you can then get a little picky and look at the other factions - Dead Orbit, FWC or New Monarchy - and grind one that has gear more to your liking from a stat perspective. Or you could do the other "main" faction (ie. - if you do Crucible, you could then rank Vanguard) grind to Rank 3, mainly for even more Leg weapon options. Hope that helps!