Nowadays, melee advs don't need to spend as much on IPs as they used to--you can go to Tsunoyoshi Smith and pick out what specials you want on your Meibutsu Daitos, and ignore brawl and dimach (dark blue) if you want. 1he advs are more focused on fast and sneak attack now than before, when they were forced to take brawl (due to SOL executioners and other older 1he weaps).
I think the best bet for a melee adv is to use Meibutsu Daitos bought from Smith starting from level 1, and use them until you outgrow the highest QL that Smith sells. He sells up to QL125 or 130 or something, so when you're high TL3 or low TL4 you might want to start looking into different weaps. SOL executioners are decent after that, though maybe nasty for IPs. At 125, you can get into IS and look into getting one of the three weaps there--Frost Shards, Icebound Hearts, or Gelid Blades. Those three are all great. Mantis Scissors used to be popular before IS, but those have a 146 level req on them. Some people like to dual scissors with a different weap just so they get sneak attack, which is nasty in PvP.
For pistol advs...BBI Faithfuls are pretty good for damage at low levels, and easy to get hold of (sold in trader store and they're rollable). Customized Desert Reets are a must-have once you can get them in the 40s, and you can use those for a long time, as Indef said. After that, you can get into flux pistols, or some of the IS guns--Prelude to Chaos (adv only), Parasitic Hecataleech (pistol/burst gun), Right Hand of Entropy (also adv only, good luck getting this sucker). When you hit 175, you can use the Patty guns. The PoP is sort of useless in SL, but the RoP is a little better, at least against hecklers. (Hecklers are strong against PoP fire AC but weak against RoP chem AC.) If you're an atrox adv, there are the Kick Pistols, but ask Meenie about those.
And of course if you get lucky, you can get hold of the Jobe Surveyor/Explorer Personal Pistol. Good min damage plus Full Auto. Happy camping!