According to similar sources...

http://www.youtube.com/watch?v=Om3WP_Ncjac

...in Syria, there are:
- 115,000 insurgents organized into 1,500 different groups (why care about 'umbrella' organizations? it's more favourable to present the insurgency as '1,500 different groups'... )
- 7,500 of these are foreigners, from 74 different countries
- 70 of foreigners are US citizens
- (more than) 1,000 of these 7,500 foreigners are from the West.

Overall, less than 10% of combatants fighting on 'non-regime' side are 'foreign Jihadists'. Hardly any of them are involved in fighting the regime (on the contrary, the ISIS attacked Abu Kamal yesterday morning, causing heavy losses to local insurgents, and then went on to slaughter 7 captured insurgents and 21 civilian activists and supporters of insurgency; man, they ought to be more effective than the Air Force Intelligence...), but well, they're a 'more pressing issue' there, obviously.

Correspondingly, this much of 'US arms and aid' is provided to insurgents:
Syrian Rebels Find Support, and Frustration, in Jordan
...When rebels want to return to Syria to fight, Jordan’s intelligence services give them specific times to cross its border. When the rebels need weapons, they make their request at an “operations room” in Amman staffed by agents from Jordan, Saudi Arabia and the United States.

During more than three years of civil war in Syria, this desert nation has come to the world’s attention largely because it has struggled to shelter hundreds of thousands of refugees. But, quietly, Jordan has also provided a staging ground for rebels and their foreign backers on Syria’s southern front. In the joint Arab-American operations room in Amman, the capital, for example, rebels say they have collected salaries as an incentive not to join better-funded extremist groups.

But this covert aid has been so limited, reflecting the Obama administration’s reluctance to get drawn into another Middle Eastern conflict, that rebels say they have come to doubt that the United States still shares their goal of toppling President Bashar al-Assad.

In fact, many rebels say they believe that the Obama administration is giving just enough to keep the rebel cause alive, but not enough to actually help it win, as part of a dark strategy aimed at prolonging the war. They say that in some cases their backers even push them to avoid attacking strategic targets, part of what they see as that effort to keep the conflict burning.

“The aid that comes in now is only enough to keep us alive, and it covers only the lowest level of needs,” said Brig. Gen. Asaad al-Zoabi, a Syrian fighter pilot who defected and now works in the operations room.
...
Considering nobody there gives a damn about finding people like Austin Tice, while at the same time there are certain retired Generals who are 'loudly thinking' about supplying stored B-52s to Israel too, I most sincerely hope that nobody got his tie dirty...