The skeleton on a sorcerer can have so many setups that you can pull off successfully it aint funny. So saying you want a dd build skell is still a bit sketchy because there is more than one way to make a dd build skell.
Dirk/atk spd ddOne of your major decisions will be if you are going to incorporate the passive speed buff from wearing hunter armor and then complement it with the active skill feast of the wind. This combo can then be buffed by combat support to create and extremely fast attacking skell and blood aura to have the maximum damage possible. Given the right weapon such as a dirk, the skell would become a dps monster especially with further weapon speed buffs as well as the other str/patk/additional damage buffs. This build is also a strong anti caster build in pvp and seiges.
The downside to this type of dd skell is that when it is not fully buffed it will not be as damaging e.g. outside the dungeon in solo. It also will not be able to maximise the damage from skill spamming since it will lack the patk of a 2h axe for instance. So moves like blow of rage and poison blow won't be as damaging with a dirk as with a 2h axe. However due to the high dps while buffed this point is somewhat nullified not to mention these skills would also add to the dps. The biggest downside will perhaps be the fact that you are using hunter armor. Immediately your skell defense will be lowered by using the hunter armor (though you get a slight movement speed boost). However I guess the faster you can kill the less hits you will take but be assured that there is a vast difference between the tanking ability of a skell and a tortus even as high as lvl 100 evo2.
2h axe/pure power dd aka the skill spammer The main choice here is the 2h axe and to be quite honest it was my weapon of choice right up to R4. The other main focus here is to level up the skills blow of rage, thunderbolt and fighter slash as high as possible. At higher levels you will also get poison blow and some people do go for blast however that is highly debatable and optional. I suggest you ignore blast. You will need it to get Fighter slash but I guess you can do without fighter slash as well. This build does not require atk spd speed however If you want you can still get hunter armor and get feast of wind. The buffs here will be power support and blood aura once you get it. The beauty of this build is once you use moves like poison blow (+ it adds poison) and blow of rage which double your damage and thunderbolt which is even more damaging + stun. Even fighter slash and blast will do some nice damage at high levels on this build.
The downside to this build will primarily be the jps spent on levelling the skells attack skills especially if you add in blast and fighter slash. This build is not as defensively challenged if you go without the attack speed passive and simply use warrior armor combined with vit and str stones.
The balanced warrior/ spear/ 2h swordThis build is the versatile build and its really a build it to suit yourself type build. Your choices here reflect how you want to use your skell. You can either go for speed, power or a combination of both and is in fact my current choice of skell. It is in fact not as much a dd build as it is a utility build which is why I did not include dd in the heading, yet it can dish out the pain just fine anyway

It wont beat the fully buffed dirk for dps or the 2h axe power build for shear hitting power but it does allow you to switch up from time to time how you want to use your skell which for me is optimal. I am not promoting this as the best build so don't get me wrong. It works for me simply because my idea of how a sorcerer works is that I see me and my pets as a combination/team with no main character but instead versatile trio capable of adapting to any situation seamlessly. So my utility build allows me to move from solo, to dp to pvp (and even if future events allow, seiges) without having to change weapon or armor. It allows me to also use any type/combination of buffs to suit what is nescessary without limiting my other pet. E.g. If I use my red pixie, which I currently have listed as inactive, I can use aura of halisha without seriously detrimenting my skells attack, with a combination of either combat, power, spirit or magic support.
One other small point is that by using your skell as a dd you are inclined to use str stones however for lower level skells especially if they will be your main pet I think that nothing is wrong with sacrificing a little attack power for a agi/vit stone build.