Who are our ranged harriers?Four classes fit well into this methodology - the three striker classes for their high damage, all of whom are capable of acting at range, and the wizard for his AoE debilitation and minion killing.
The WizardRaces: Elf gives you Elven Accuracy, a good dexterity, a good wisdom, a sight advantage (LLV), and a movement speed of 7. All of these are potentially useful to a skirmishing wizard. What it doesn't give you is an int bonus - for the moment we'll forgive that because its other advantages make up for it (and we're not getting that 7 move speed anywhere else!).
Your other real option is gnome, which gives you some great stealth abilities and an int bonus, but that hardly makes up for everything it loses.
Its perfectly possible to play a standard orbizard build in this role. See my Wizard HB Master of Puppets concept. However, we can optimize more specifically at the loss of some generality.
You're going to be focused on early combat performance, which makes elven accuracy really good. In addition, starting with wand of accuracy isn't a terrible idea (we can pick orb up in paragon). Especially as you aren't going to necessarily be trying to save-lock someone for an entire combat, just long enough to let you annihilate most of his buddies. As such, a 16 int 14 wis 14 dex 12 cha build pre racials can be justified - especially as you will likely be getting a lot of use out of Sieze the Moment in paragon by party SOP (assuming you have it). We'll also probably end up using a lot of Master of Space style spells, so the utter dedication to orb will not be as heavily rewarded as it could be.
Your spell choices should focus on spells with a range between 10-20 squares. Certainly spells which have a range of "close" should not be common in your repetoire (although having one as an 'oh shit' button isn't a terrible idea). You should also favor spells which create favorable terrain or disable the enemy. Sleep is a beautiful spell because it still slows (save ends) on a miss - the hit text is just gravy. Icy Terrain is a great encounter power because it creates an obstacle to the deployment of force by the opposition. Similarly, Grasping Shadows from the Class Acts article. At later levels you'll want to take advantage of spells like Web, Wall of Fire/Ice, Illusory Wall, and so forth. Your goal is to break the enemy up into manageable chunks so the party doesn't get overwhelmed.
Your At-Wills want to be Scorching Burst (for minion control) and probably Ray of Frost (because slow is really powerful in this style of party).
PP: Bloodmage is almost certainly your best PP option, but DO is also strong (especially if you can take Illusory Wall!). Ie, typical wizard PP choices.
I recommend two wizards for reliable control options.
The RogueSniper Rogues (Gleemax), probably Drow for the stealth advantages. Your best PP is probably the Assassin, because you want to focus on massive damage.
The RangerRace: Elf, duh. Bonus to Wis and Dex is exactly what the doctor ordered!
You're an archer ranger, there is nothing unusual here.
The WarlockDrow and Gnome both make exceptional Feylocks, which is probably what you want to be doing.
Githyanki makes a good Hellock, but isn't notably stealthy nor notably fast, but it does do more damage and could quite possibly tank if forced to melee. Actually, at that point something like a Minotaur Hexhammer is both a serviceable ranged skirmisher and a decent tank, but this is a compromise build for this party style. Feylock is almost certainly the right choice, although starlock (with charisma focus) could be ok (no eyebite, but it's probably still doable). Your goal is to end up invisible or otherwise hidden at the end of each of your turns, in addition to churning out some serious damage and, quite possibly, some disruption.
Your power choices should focus on making the enemy lose actions or dealing lots of damage.
PP: possibly multi into rogue for the Daggermaster PP to pump your critical with a pact blade, and write off the PP powers.